I sure would like a birth certificate, a death certificate, and/or a gravesite for Arthur Mould, who is represented in different LDS accounts (all we have) as born April 26, 1869 in England or in May 1870 in Utah; dying July 24, 1877 in England or in Utah; the son of William Ashdown (physically impossible for either birth date) or of Thomas Mould.
I think the appearance of an infant Arthur "Spencer" in Jane Spencer's household (next door to her brother Alfred Spencer's household? part of the same household?) in the 1870 U.S. census for Centerville, UT may be the sole documentary source for the connection between Jane and this unfortunate little boy, who in all accounts dies at age 7 or 8. Was Jane pregnant with him when she set sail for America in September 1869, giving birth to him in May 1870, as the census records? Did she give birth to him in England in April 1869 and leave him with his father? (If not, where did the very specific birth date of "April 26, 1869" come from?) Or is this Arthur on the census in Utah a different Arthur, perhaps the child of the 40-year-old "Clara Spencer" (presumably Jane's brother Alfred's wife) in Alfred's household on that same census? Even allowing for Jane reclaiming her maiden name and giving it to Clara (and to Arthur?), there are at least two inaccuracies in this census account: (1) The 5-year-old Clara was not born in Utah; and (2) Jane was not a widow in 1870. But the complete invention of an infant who wasn't there is beyond the pale. So who is this little boy? I could believe that Clara Spencer (the older one) named a child after the boy that Jane left behind in England (after all, it is possible that Jane named her little girl after this elder Clara, having presumably corresponded with her and Alfred before Jane and little Clara's emigration), but I'm not prepared to believe that both of the little boys died at 8 years old, neither of them with a birth certificate, a death certificate, a grave, or any evidence of their whereabouts after 1870! Where did the "July 24, 1877" death date come from?
WJ Mould said he'd already scoured the UK's free BMD indexes and came up empty handed.