What an awesome H&R! I remember the A grade Brad and I restored well. Serial number 50. Prior to that I had only ever seen lower grades like C or D. The NRA museum in Fairfax, VA has at least 3-4 on display. The attached pic is my poor ink pull prior to prepping the receiver. Looking at it now I wish I would have used plain white paper to stick the tape to. From my notes on the back #50 was unique in that it did not have a traditional extractor retaining screw in the barrel lug. We speculated #50 was either the first A grade or one of the first H&R doubles built under license. It would be interesting to compile a serial number list to better learn production numbers. The others I have seen all had the retaining screw and seemed to be at least three or four digit serial numbers. My note also included “26” Damascus barrels, bores appeared to have been honed”.