cpw will know, as president of the HP collector's association and having the biggest and rarest collection known, about 200 including number one and those with a swing link like a 1911 and those with small ejection ports, rare cotracts, etc.. He and mr V. did not see eye to eye on many things, including Radoms, his knowledge is written down somewhere I hope, . We must not loose that knowledge. I have told him so but he stays very busy. We set up toghe often at SOS and NGD and for many years. I would use him over mr V anytime. He is at the top of the field IMO and I have seen much of his collection. He need not write a book, those that know him and his collection of both Radoms and Brownings know who the source is. If you see his collection, which he displays both type pistols at times, you will also know very quickly.
I asked him this exact question 16 or more years ago and he had no definite answer. I have looked at many and it seems that the paint was come and go for quite a while. They all needed it IMO. I had a mid production gun, and early A block IIRC and it did not have the paint. All around the edges of where the paint should be, it had light pitting. They needed it and it was stupid to not use it. The workers at FN probably could care less unless they had a Nazi pistol at their head and someone knew what should be.