As per the Dillers you mentioned that were buried in the Lebanon, IL cemetary, I wanted to comment on the descendants of Uriah Diller (b. 1779), descendant of Francis Diller.He did have a son named Jacob Diller, but the sources I have state that this Jacob was born on 1 Feb 1817.This would seem to eliminate him as a possibility for being the same Jacob in the cemetary.
As for Uriah Diller, he and his descendants moved to Niagara and Erie County, New York.I just don't have any record of your Jacob (or the McGarvey surname) in Francis Diller's line.
You know, there was another Diller family that was separate from the Francis Diller line.This is the Caspar Diller line.Caspar immigrated to America in the early 1700s and he died at Loch Platz in Lancaster County, PA in 1770 or 1775.He had many descendants who lived in Lancaster County.There is an old book written by J.L. Ringwalt that details this family's history.I procured a copy of it through the "Higginson Book Company" (you can find them on Cyndi's List).At any rate, I went through this booklet tonight looking for your names, but did not find any matches.The only descendants I could find that went to Illinois settled in Sterling, Illinois.Sterling is nowhere near St. Clair County.Also, I could find no descendant by the name of Uriah.
I guess this post won't be much help to you.I just wanted to let you know what I looked at and what I didn't find.I do agree with you, however, that the Uriah name would seem to connect your Dillers to the Francis Diller line.