Frank, I’ve tried contacting Ira at Big Bore without any luck. Do you have any contact info? I might not have the correct site. Thanks, AnthonyYou may want to contact Ira at Bigbore.com. I don't have an email address but you should be able to find it on the site? Ira deals primarily with DD stuff and the M3 parts are something he comes across from time to time. Lots of the guns are registered in the US and there are breech rings and stuff out there. Building up a shooter is a great idea and the guns are great fun to shoot. They're a bit heavy compared to the Bofors 37 but they are great guns.