To just use the drum you can get some all thread rod and acorn nut for the end. Get the all thread rod the same thread as the shell nut. Cut the all thread rod to size and that should get you up and running whuile you look for the correct parts. You can use a spare bass drum lug casing spring or the likes cut to size for the spring. You can use your fingers or a socket that fits the acorn nut to tension the snares for now. The good thing is I see the tension side parts fairly often on ebay. It's the throw side that is harder to find. Good luck!! And please post some pics!!

BTW...Jim Petty makes and sells some of the Clamshell parts. Not sure of he makes a tension side rod assy though.