I, too, am descended from Charles Taintor who came to America from Wales.I also have the Charles M. Taintor book of 1847 (copy of original) and have looked for "proof" of the Wales heritage.
There are Taintor's listed in the 1881 Wales Census online at the LDS site & there are files containing Tayntor's, Tainter's & Taintor's pre Charles the first, who came to America, listed on the LDS site at the Family Search, so this leads me to believe that the book MIGHT be correct, of course who knows for sure.
Here is a Tainter in Wales, married in 1808: RICHARD TAINTER MaleFamily Marriages: Spouse:JANE MORGANFamily Marriage:06 AUG 1808Merthyr Tydfil, Glamorgan, Wales
But, like you, I have not seen a real history that proves we originated in Wales.My Dad always said the Tainter's were Norman's who came to Wales.And, that Tainter/Taintor/Tayntor was French in origin and meant to "dye" fabric & that we must have had ancestors who worked in textiles.
But, who knows?We do descend from Charles, who came to America & was one of the CT Freemen and most can't go back this far in their history.
Isn't it wonderful Charles M. Taintor recorded this history in 1847?