.... especially in consideration of the many times people have said that (paraphrased) "period documents don't tell the whole story."
I've wondered for a while who served as gunsmith at Fort Augusta after William Henry (who was there in 1756). Joseph Shippen's letters refer, I think, to a gunsmith or gunsmiths, but he does not name them and who these gunsmiths were had not been discovered.
I stumbled across this (see below) at the Historical Society of Pennsylvania this week, which helps answer that question. Digging further once I found this, I found quite a few records of payments to Gehr for his work at Fort Augusta between 1761 and 1763. He seems to have left there in August 1763. Other receipts identify a man named Joseph Brown as a "smith" at Fort Augusta during the same period.
These provincial assignments (armorer at Fort Augusta, say) sometimes enabled manual laborers such as Gehr to make connections with important people, which they could leverage later. Henry used his connections with the Shippens, presumably established in 1756, to escape hard labor at the forge or at the bench altogether. We don't know enough yet about Gehr to see what he did with these early connections.