Chris,
Thank you very much for posting photos of your Joe Long rifle. Great looking example of his work. If possible, please post a photo of the sideplate area of your rifle. Two lock bolt JL guns are rare has hen's teeth. I would also be interested to see a photo of the toeplate area. As mentioned earlier, JL guns with original flintlock are not typical. Perhaps your gun is one of his earlier guns? Maybe, his client was just an old-timer that didn't take to the new-fangled percussion cap technology?
Stoner Creek,
Thank you also posting photos of your rifle. Is that a push button release on the patchbox lid? I believe I see a button protruding from the toeplate. This would also be an unusual feature for a Joe Long gun. Most, maybe all, of the other Joe Long guns I've seen have the typical Upper Susquehanna lid release that goes through a hole in the back of the buttplate, like the one seen on Chris's gun.
Mark