Yes, I agree with both comments. The piece I linked to in that first post tries to show this is just the case with William Henry II: for many years, at least according to the Nazareth diary, his primary occupation was joiner and he seemed to request (several times) to "begin again" his trade as stocker, which suggests that (for a time at least) he had abandoned it entirely or severely reduced his activity as a stocker.
His son John Joseph Henry becomes the first "full-time" Henry gunsmith, first in Philadelphia and then, after 1812, at Boulton. (His brother, William Henry III, helps build Boulton but abandons gunmaking relatively early and, generally unsuccessfully, tries to follow other trades/professions.) J. Joseph Henry's descendants (James, Granville) continue as professional gunmakers, and I think our tendency has been to see the earlier figures (WH I, WH II) as involved similarly in the gun trade (instead of recognizing, as Joel and Bob said, that they were involved in many activities and gunmaking may not have even been their "primary" activity or identity).
I would love to be able to know--with reference to William Henry of Lancaster--just how much he did continue to work as a gunsmith in the 1760s. If at all. His brother John (died 1777) was a gunsmith, owned a boring mill (I think), etc. The (still unpublished) minutes of the Lancaster County Committee of Observation (1774-77) frequently lists John Henry among gunsmiths they are communicating with, but never William. My sense, largely speculative, is that William Henry spent most of his time/energy on his iron importing business/hardware store, until the war brought him back to the gun business (in a different capacity: not as a producer but as a organizer/supplier).
There was, at some point, considerable effort expended to discover Henry's "gun factory" near Lancaster: L. D. Saterlee was on this hunt during the late 1930s. I suspect that any factory asssociated with him dates not from when he was an active gunmaker himself but from when he was organizing gun production during the Revolution.
Scott