Hi Jane,
Yes! You are correct--it might be he. I suppose if someone else were giving the information to the census taker, the age could be off by quite a bit.
The Thomas Tear account seems to have him at the Vermillion furnace, and not in Cleveland, but, then again, he seems to have been a bit (!) unstable, and moving around a lot.
I think he is the William listed in the 1850 Leroy census: William Tear, Jr. 34, Catherine 30; Esther 9; Martha 9. (He is not the first that I have seen enumerated in two places.)
Thanks for your help!