I have Contender frames in both Armour Alloy and Blue. The AA hinge pin was 0.3722" and I found that my blue hinge pin (0.3739") would fit my AA frame, so with careful use of 400 and 600 grit sandpaper I opened up both my AA barrels to accept the blue pin. I replaced the blue pin on the blue frame with a stainless pin of 0.3744". The SS pin does not fit the AA barrels or frame.
So I now have two frames, that I can interchange barrels on and snug fitting pins to boot.
I love the AA finish, it has a lubricity to it not found on stainless frames and barrels clean up easily after a shooting session, even with lead bullets.
I bought my second barrel cheap from Ed's but on ebay the AA barrels seem to go for a premium.