If you have or come across reasonably priced Mamiya C series gear that works, it's probaby a good buy and may last for years. But before fooling much with faulty gear, I'd invest in current equipment that's supported by the factory and local repairmen. If parts are needed for C cameras, you're likely out of luck unless there's another camera around to cannibalize. And some repairmen won't even accept C gear anymore because of the parts situation. However, various conditions of C bodies and lenses still reside in many used-equipment shops.