I have a flint rifle with J. Henry, Phila. stamped on the top flat. The rifle has a nice engraved patchbox and a Drepert lock. In reviewing the books, I note there were quite a few Henrys building Kentuckies. There was a J. Henry associated with Lancaster, a J. J. Henry, etc. Is anyone familiar with the J. Henry that worked out of Philadelphia. I recall reading where the Drepert locks were made in Lancaster. Is that correct? Anyone know what period of years?