Thanks for getting back to me. About a month ago I contacted the Welsh National Library's Genealogy Department to look for any Taintor 'Welsh' links and they found none (although I only provided them with basic background information just to "test the waters"). I did, however, come across a reference in Ken & Mary's Genealogy Report (page 5 0f 192) under notes for Michael Taintor compiled by Ruth Ellsworth Richardson in 1974 that says: "Taintor is an occupational surname from taintorer, a dyer. The family has been represented in England since 1222".
This is the first reference I've found that might show any promise as to linking the Taintors'across the Atlantic. It's a starting point so I thought you would be interested if you weren't already aware of the passage.