I just bought a Model 67, serial number C309731, and I have a few questions about it. I tried doing research on the gun but Im reading alot of different things.

First, anyone know what year this gun is??
Second, can i take off the barrel and replace it with a ribbed barrel with a removable choke?? If so, where can I find one??
Third, what is the built in choke on the stock barrel??

Any information on this gun is much appreciated, Thanks.

Ty
"Semper Fidelis"