I own a Nikon FM2 purchased in the year 1985. Its shutter speed mechanism behaves totally erratic. If you set at 60 (i.e. 1/60 sec), shutter operates at s 1/4 sec ! At the top speed 4000. it takes 1/8 sec ! At 4, shutter opens OK, but refuses to close! i.e. the shutter mechanism is totally out. How and where can I get it working OK again? :heart-borken: I live in Chennai, India.