Hey aerowelder,
I see you also have discovered the realm of diecast(potmetal) and the associated frustrations that go with it. Listen, there is an answer. About 5 years ago, I discovered a fellow in Hurst, Texas....Charles Kimbrough who solved the problem to repair diecast metals. He has an E-bay store, Surplus Rare Earth Magnet Neodymium. He sells the rods that will cure your problem. Back when I got some from him, they were labeled HTS735. I believe he has changed the designation. Anyway, you can look at his product by going to E-Bay and typing in the item #260173747923 and read his informative description. Believe me, they work.....you gotta do some practice on some scrap to get the "feel" of it. It can be done quite well with just a propane torch, and if necessary on thick material(>.500), MAPP gas would suffice. I found that if I clean the metal as I do with aluminum, the welds are very strong. I have repaired many diecast items without a failure or a return. And, I do charge an adequate fee for those repairs, as they cannot be repaired any other way. Diecast is really a lot of garbage metal which includes zinc, manganese, brass, copper, aluminum, iron, and any other garbage material they throw in the mix. It is just the residual scrap that is unusable for any other application and is utilized to make inexpensive products including many auto parts. Anyway, I hope this may help you to solve your problem.....Good Luck....Denny