I'm not sure if I am thinking of the same person, but as a child, we visited the Conrad Weiser homestead in Womelsdorf, PA. The curator took one look at my dad and said that he could tell Dad was a Weiser. He proceeded to take us to the attic and show us a portraid of a Reuben George Weiser. This man was a dentist.I'm not sure of his birth date, but Conrad Weiser was born in the 1700s.You might want to contact the homestead to see if they have further information on Reuben.
Suzanne Weiser Gausman
ps - incidentally, my dad (George Reuben Weiser) bore a STRIKING resemblance to Reuben George. It was uncanny!