I have 4 of them with 8 barrels and do not need any more. But 3 came in today for various problems and I will repair them.My comment was simply to make a guess,somewhat educated, about the costs.The good news is that I,and any others, can get parts and the 21 is a good foundation for a rebuild. It is not an elegant shotgun,but I first lusted for one in 1957 and now own the "Mack Truck" of shotguns,four times over.