There is much written on the message boards that if you haven't done so already it might help you sort these individuals out.The authority on your William Iiams b. 1750/5-d. 1831 who married Elizabeth Unknown would be Darius Brant.I haven't corresponded with him for a number of years but his research is outstanding. William Iiams mentioned above is definitely not a son of Thomas Iiams b. 1708 as his son William married Charity Ryan. I believe that there has to be a generation from Richard Iiams b. 1673 and William Iiams 1750. I don't think that I have much more than you do.