16 ga Repro

[MD*GSP]

I have a thread in the wtb section but figured any discussion/q's should be here in the Reproduction section.

I recently treated myself to "The Parker Story" and read that the 20/16 was offered a bit late in the game..I also read that for those that already owned a 20ga that a 16ga set of barrels could be added to it.

My question is this - if adding a set of bbls to an existing 20ga..did the factory (not offshore but here in the states) offer fitting to the frame and to the forearm? Also, were the new bbls serialized to the gun it was added to?

~Scot