I recently acquired two 1960's Minoltas - a Hi-matic 7 and a Hi-matic 7s. The Hi-matic 7s is missing the shutter release button, but works fine otherwise. Where can I find a replacement for it and is it straightforward to install. Now, the trigger (or film advance lever) of the H-matic 7 won't automatically return to its original set position. Initially the trigger was stiff, but I took the base cover off and applied some silicone spray. This helped a little, but the problem still largely remains. Also the shutter is very lethargic on this (the 7) camera. Can anyone offer assistance here. Many thanks Frank.