Thank you, gentlemen, for your insights. You have answered my principal curiosities and concerns. I have edited the title of this thread to make it a little less misleading. I had, of course, been operating in the world as described in Kindig's Thoughts... in which there were two Christian Becks. From descriptions in reference books and ALR, it appears there are at least four, though so much is contradictory.
Following Kindig's observations, I had allowed the construction of the patchbox - with the side plates of the patch box overlaping the sides of the hinge and position the patchbox release in the butt plate and the iron catch in the upper rear corner of the lid - to direct me to 'Christian Beck - the Earlier.' Obviously, now, this was wrong based upon the late lock, which does appear to be original to the stock as Christian Beck of Lebanon passed away in 1803. So, thanks to Mr. No Gold I'll follow the attribution that this rifle is late work of J.P. Beck's son C. Beck and that should account for style of the patchbox and the date of the lock. Maybe Chandler #90 and 91 are also this man's work?