I bought a 59A last spring for $50. Then a couple weeks later I bought a complete 8RT for $400 including the engine stand it had been on since the late 70s.
Ive used both....the putty is easier to work with when using it on a vertical surface. I use to rebuild broken cases on motorcycles in the point cover area with JB weld. It was a challenge to get it to stay where you wanted it until it cured.
even better way is to use POR-15 epoxy putty. Two clay bars you mix equal portions together and when it hardens it is very tough. You can even drill and tap holes in it. And to make it smooth just wet your finger and smooth it out. It will even cure under water.