Early Hasselblads are beautifully made; in fact, probably engineered to a higher standard than the later equipment.
However, buyers do need to tread with care. Any camera that's 50-plus years old will need to be checked and tested very carefully. In this video I run through how the 500C differs from later cameras and what to watch out for when buying.
I hope you find it useful and please do contact me if you have any questions.