Your good to point out the Everett Thomas material. The Everett Supplement available at Heritage Quest on line and also at the Fort Wayne, Indiana Public Library which I believe was the source of the copy on Heritage Quest, has some very helpful and valuable research, especially the notes from Barbados and the Islands in the Carribean. If I remember correctly, though I would need to go back and reread the Everett Supplement for sure as it has been a while since I last read it in detail, I seem to recall that the researcher of this work may not have understood that two of the cousins named Christopher Thomas of County Kent came to the Americas at about the same time.
There was Christopher Thomas who was Christened at Sundridge in 1609 and had a son named Tristram who was born ca. 1633. The father and the son arrived in Virginia in 1635 but appear, from records in England, to have returned to Kent where this Christopher eventually died. He, Christopher, was the son of Tristram Thomas (d. 1640/1) who married Elizabeth Saxbies at Westerham in 1601 and was a Uncle of Tristram Thomas of Talbot.
Then and then there was the Christopher Thomas who appears to be the eldest brother of Tristram/Trustram/Trystram Thomas of Talbot County, Maryland, the latter of whom was the principle subject of both the Spencer book and the Everett book. This Christopher, who was Christened at Westerham, Kent in 1614, "grew up" at Orpington and then apparently died in Talbot County, Maryland in 1670 also came over to America, though with stops at Barbados, at about the same time as did "Christopher of Sundridge;" but like "Christopher Thomas of Sundridge," he too returned to England, probably about 1636, based on records in Kent, following the death of his father Christopher Thomas (1579 Chevening - 1636 Orpington) in ca. 1636. However, unlike "Christopher Thomas of Sundridge," this latter Christopher Thomas, "Christopher Thomas of Barbados Hall", brother of "Trustram Thomas of Wye River, Talbot County, Province of Maryland, Gent.," returned once again to the Americas, landing in Maryland around 1665 with his wife Elizabeth and his step-children Susan and Katherine Higgins.
The two are also easily confused along with their cousins "Mr. Christopher Thomas" of "Seven Oaks, Kent (1598-1678), and Christopher Thomas (Chr. 1630/1 at Chevening) who was a son of "Christopher of Seven Oaks.".
Almost all at one time or another have been claimed by researchers to be Christopher Thomas of Barbados Hall who died in Maryland in 1670 and at least three of the four have been claimed to by the father of Tristram Thomas of Talbot County. Similarly the many Tristram Thomas's of Kent are also easily confused. There's the uncle of "Trustram Thomas" of Talbot, "Tristram Thomas of Brookes Place" who died ca. 1640/41 and married Elizabeth Saxbies at Westerham in 1601, and was the father of the previously mentioned Christopher Thomas Christened at Sundridge in 1609; and then there was this Uncle's son named Tristram Thomas (Chr. 1606/07) at Sundridge, Kent; and another grandson of the Uncle, Tristram Thomas Chr. at Chevening in 1626, son of the Uncles's eldest son, Edmund Thomas (d. 1660).
So there's plenty of reasons for confusion. Fortunately for researchers of Trustram Thomas of Talbot County, Maryland, there is a fairly substantial body of evidence showing that Tristram (or Trustram Thomas as he signed his own name once in Maryland) is the "Trystram Thomas" who was Christened at Orpington in 1629, the son of Christopher and Juliana (Stacey) Thomas. Probably the most significance pieces of evidence (several land deeds, wills, and estate records in Maryland coupled along with marriage records, wills, Christening records in London or Kent) are those which show that Major William Coursey (d. ca. 1684), who referred to "Trustram Thomas of Wye River" as his "beloved bro-in-law," married the twice widowed Juliana (Thomas) Beedle Russell, thus providing an explanation for the reference by Major Coursey to Trustram Thomas as his "beloved bro-in-law" in a deed of gift dated 1670; and with none of the other "Tristram Thomases" of Kent known to have a sister named Juliana, a conclusion that Trustram Thomas of Wye River is Trystram/Tristram Thomas of Orpington and Erith can be made. In conjunction with evidence tracing the whereabout of the other men named Tristram Thomas and a relatively strong proof can be established. There is of course little in genealogy that is "Absolute."
[Note: To the best of my knowledge, and I've researched this family for well over 30 years, I've never found any evidence that Major William Coursey had a sister named "Anne" who could have been Trustram Thomas's wife named "Anne" and thus explain the reference to "bro-in-law" in the deed of gift. I've heard countless claims of such records that do supposedly show and prove Major Coursey had a sister named Anne, but I've yet to find anyone who has been able to produce the evidence. I'm certainly willing to look at it though if someone has it!
ALSO, another false claim that is frequently seen on the Internet is that a genealogist hired by Mrs. Mary Pirie, found proof that the marriage record in England for a Tristram Thomas of Erith, Kent, to an Ann King, was not for Tristram Thomas who died in Talbot in 1686. The fact of the matter is that while there was a professional genealogist who did make this claim, he/they worked for the late Mr. James McClelland of St. Louis, not for Mary Pirie. Mary did pass the information onward as she and Mr. McClelland freely shared information and they inturn then freely shared it with others in their respective research "circles.". HOWEVER, the genealogist Mary had hired, the very competent Mr. Sydney Smith of Orpington, Kent, did find significant evidence indicating otherwise, and that to the contrary, the marriage record was in fact the marriage of Tristram/Trustram Thomas of Talbot County, Maryland and his wife Anne.
The other genealogist, that hired by Mr. McClelland, seemed to have jump to a conclusion upon finding the will of a Tristram Thomas in Middlesex County in the 1690's who had a wife named Ann too, but Mr. McClelland's genealogist apparently was unaware of the marriage of a Tristram Thomas to Ann Swan at Greenwich, the latter of which was too late to be the marriage of the Talbot County Tristram Thomas and in addition, it's location better fits for the Tristram Thomas who died in Middlesex County too. Furthermore, there is strong evidence showing that Tristram Thomas of Orpington who was Christened in 1629 did move to Erith (Along with his brother Stephen Thomas and possibly another brother too), before coming to America, and thus could be the Tristram Thomas is listed as "of Erith" who married Anne King in 1652 in London. Erith not having extent parish records from this time period is a hindrance though, but the absence of the records also explains the lack of anyone, at least to my knowledge, having located the birth records of the three oldest children of Trustram and Ann Thomas (Thomas Thomas, Christopher Thomas, and Tristram Thomas) who are listed with them when they arrived in Maryland in 1666.
Another place in which both Mr. Spencer and Mr. Everett and their researchers became confused was with the claim that Edmund Thomas (d. 1627) "the Royalist" who was Trustram Thomas of Talbot's grandfather; and Edmund's brother, John Thomas (d. 1603), who was the grandfather of Christopher Thomas of Seven Oaks (1598/9), were the sons of a supposed Rev. Tristram Thomas born in 1550. The Rev. Tristram Thomas, research has shown was actually the Rev. Thomas TRISTRAM, NOT Tristram Thomas, and thus NOT, or at least not likely <grin>, the father of Edmund Thomas and John Thomas and their possible siblings including several sisters. There is evidence that indicates this Thomas family had long been established in County Kent, but I've not been able to prove, at least to my satisfaction, the line further back. That of course doesn't mean the evidence for their father doesn't exist, or that someone else may have had better success!]
Nevertheless, both books are remarkable efforts, especially considering the dates both books were published, respectively. Even the "Genealogy World" of the 1960's when the Everett supplement was published was a very different place than today from a standpoint of the ease of research; AND regardless of mistakes and errors, both books CAN be very valuable for any one attempting to connect on to the line.
One note for anyone attempting to log on to Heritage Quest. Having a "Firewall" often does cause problems in logging on to the site, so if you're having trouble getting on, that's a good place to look for the cause. You'll will need to write an exception for the site so that you'll be allowed to connect to the site. Also, the Spencer book and the Everett book are not the only books on Heritage Quest with connections to this particular Thomas family, which a "search" will show.