Your biggest problem is likely to be the surname WILSON itself. This is so, so common in this part of Cumberland.
Some Wilson families were Quaker; and the Brigham Anglican registers do include some Quaker events. However, as you've got a baptism, that's an unlikely scenario.
If you've only got your info from the IGI, then it's worth getting a transcript or film of the Brigham/Lorton parish registers (Lorton was a chapelry of Brigham, so their BMD events can intertwine). The film is available from the LDS. If you've done that already, fine.
You may well find that the years you need are missing. The BTs for Brigham certainly have some crucial gaps (1677-1688, 1693, 1700) according to the National Index of Parish Registers Vol X; but the parish registers may be more complete.
You've certainly got one problem. The probate index compiled by Neville Ramsden lists two possible Richard Wilsons: Richard Wilson of Rogerscales whose will was proved in 1700; and Richard Wilson of Eaglesfield whose will was proved in 1727. A Daniel Fisher of Lorton went through probate in 1727 (no will, only a bond and inventory). These are all available on LDS film. It so happens that I have the film for the first will on indefinite loan at the South Kensington FHC and was intending to look at that actual will in due course, so I'll try to do so on Thursday or Friday. However, he is unlikely to be the right one - as the probate doesn't include any provision for minors.
(these cover the Brigham/Lorton area)