I'd just caution that many of these receipts are not signed by a gunsmith: they're signed by somebody who sold a rifle to a captain (or had his rifle taken unwillingly but was reimbursed for it).
That is: all these receipts serve to document something that a captain (or some other officer) has paid for so he can get reimbursed for it. Some of it involves getting his company's arms repaired by a gunsmith.
But other receipts document that he has purchased an arm from a civilian. I think all of the receipts referencing William Levering fall into this category. So the signatures on these receipts (some of which I can't read either) aren't a gunsmith's signature. They're just the signature of whomever Levering got the rifle from.
The receipts here from gunsmiths (Dickert, Graeff, Gonter, Messersmith, Kraft, Breidenhardt, Fetter) describe the work done; the other receipts describe the purchase of a rifle (probably from a civilian, maybe from a non-associator).