Jim, According to Kindig, The Dickert family moved to Berks Co first, then to Lancaster in 1756. Jacob would have been 16 years old. Certainly old enough to be familiar with a rifle!
As for the patchbox, no patchbox, on this rifle, with all the bells and whistles it has, I can't imagine it being made without a patchbox. I think someone suggested that maybe it originally had a wood box, and the brass box is a later addition. If so, you'd think there would be signs of the wood box cover dovetails in the butt plate, and there's not, or at least doesn't look so in the picture.
I think this patchbox was pretty common/popular, and was used far and wide. One of my rifles has the same patchbox finale, although reversed top to bottom. It also has a completely different hinge and the gun has no other similarities.
Thanks for posting the pictures of this fine looking rifle Gary!
The cheek side carving reminds me of Andrew Figthorn,,,, but other things say he's not the maker.
John