I have a 12 bore "Rigby" style stalking rifle coming up if you are interested.
It will be some time before I complete it because I have a back log and my customers have to come first. I try to work on them on a first come first served basis, but the lack of barrels these days has screwed up my production schedule some
Anyway, if you are not in a huge hurry I would be happy to build one for you.
I can also do them in any other caliber up to 2 bore, but as I said, barrels are somewhat hard to get. Joe Williams dose my big barrels for me as long as they are not ordered too long for his machines, but in 8 to 2 bore you don't gain a thing with a barrel over 30 inches long.