As far back as 1960, men like Kauffman and Kindig had commented about the Lebanon school of gunsmithing. Read closely what they wrote in Thoughts on the Kentucky Rifle in Its Golden Age: "Another school of gunsmithing flourished around the town of Lebanon in Lebanon County, Pennsylvania. The men of this school--N. Beyer, J. P. Beck, and one of the Christian Becks--produced some of the finest rifles of the early period."
Keep in mind that there was no Lebanon county prior to 1813, which is relatively late for county identity in these parts. In short, it was all Lancaster County around here (Harrisburg/Hershey/Lebanon) until 1785 when Dauphin County was incorporated. Then came Lebanon County in 1813, about 90% of the land being taken from Lancaster County and a thin sliver taken from Dauphin County. So a man like Beyer in South Annville Twp. paid taxes to more than one county during his working period. It gets confusing, and all counties have a claim to this particular builder. Kindig was focusing especially upon the J.P. Beck and N. Beyer products and on the assumed and suggested master/apprentice relationship of the two.
I state my subjective opinion on this apparent master/apprentice relationship. Based on personal observation of many of the best examples, my eyes and records strongly suggest, even in the absence of documented evidence, that it is reasonable to conclude that some direct relationship existed. This assumption is based on a preponderance of empirical observation. The blatant physical characteristics of the hands of Beck and Beyer are so close, both in execution and detail, that my guess is that most juries of informed associates would agree.
Beyond that, as Scott Shea has appropriately mentioned recently, the "Lebanon school" is elusive and individualistic, at best loosely bound by region maybe more than by strict stylistic similarities.
That being said, here are some things that I look for when I inspect a Beyer. In addition to a distinctly "Dutchy" carving and engraving style that is easily identified after seeing a few good examples, I expect to find a closed-end muzzle cap, riveted three times in somewhat of a triangular fashion. I want to see short thimbles, compared to Lancaster and Berks norms. I would expect to see beavertails to the rear of the lock area, with three chip-carved lines inside each beavertail. The patchbox lids that I have seen have a fastener always off-center...on the upper 1/2 of the lid. That corresponds to the spring release commonly found to the rear of the lid on the plate.
Beyer was distinct. I like him because he built a classic, full-sized, early-style rifle later into the Golden Age. He appears to have been prolific and it also seems that, throughout his entire career, he continued to build rifles in the same consistently crisp manner. Note: I either have owned or seen both moderate Roman nose Beyers and others that are as straight as a downtown Lancaster, so that is not my primary hallmark of identification on these guns.
Now, please add to "the art and mystery" of the Lebanon region or comment on the characteristics of your favorite Lebanon/Dauphin region builder.