Hi I am considering buying a used Mamyia 7II with a 50ml lens (primarily due to the high cost of new). I am buying it from a reputable dealer but would like to hear if anyone has any particular things I should look out for as to the condition of the camera and lens. Is it only a matter of looking at its general outward appearance (dents,scratches etc) or there any other signs I should be wary of or investigate? What are the faults that could cause me trouble in a second hand Mamyia and lens. I understand calibration can be an issue with the rangefinder- can I determine this simply on inspection for example? Any advice or experience would be greatly appreciated.