Greetings: My 45 year old Rollei SL66 died yesterday and will be getting rebuilt over the next 6 weeks. I had a backup SLR - a Bronica - but the lenses did not give Zeiss like results so I sold it off. So I just ordered a USED 500CM and a few lenses. I understand that (like the Rollei) there are certain things you must do in order and the consequenses of doing them wrong can damage the unit. What are the 500 series do's and don'ts - I would like these tips before I get it and have to send IT in for repairs - Thanks!