A 7.62x39 M76 Fixed Tube:

http://www.gunbroker.com/Auction/Vie...Item=264976938

http://www.gunbroker.com/Auction/Vie...Item=264978577

http://www.gunbroker.com/Auction/Vie...Item=264979676

http://www.gunbroker.com/Auction/Vie...Item=264980589

http://www.gunbroker.com/Auction/Vie...Item=265008270

and a M62!

http://www.gunbroker.com/Auction/Vie...Item=265654790

They aren't cheap, but many of these are rare varients.