I don't understand why William Antes is considered a Bucks County gunmaker. He never lived or worked in Bucks.
His style is quite different than the classic Bucks gun.
I hypothesize that Antes somehow was a founder or primary influence of the Bucks County style. One not need live in Bucks county to do that. If gunsmiths who "established" the style, incorporated features found in his work which is earlier, it is reasonable to suppose a strong influence. He was a prominent man in Philadelphia during the War. But let's go to the gun, RCA 53. Note the curve to the underside of the buttstock. Not Lancaster (straight), not Lehigh (double curve). Above all, note the long wrist. The comb begins completely behind the guard reverse curve (forgot my vocab this morning). Same as RCA 61-65. This elongated wrist style almost never occurs on Lancaster rifles. Curved underside, elongated wrist, are classic Bucks county architectural features. Note the guard. Classic Bucks County. Not Lancaster. Not Lehigh. Note the use of the thumbnail motif. Often found on Bucks County guns. To me, these look like Bucks county roots. What other earlier guns display so many features found on classic Bucks county guns?
Note I do not agree 100% with Shumway's classifications in RCA volume 1, regarding Lehigh versus Bucks County, etc., and consider RCA 58 a Bucks county style gun. For that matter, makers of rifles such as RCA 52 could have influenced the development of the Bucks county style. In a "roots" gun, we are not going to see all the full blown features. In summary, I would not classify Antes as a Bucks county builder, but an earlier maker who invented and established some of the motifs found later on Bucks county guns.