I've been looking at that pic you have and the whole thing looks pretty simple (to me anyway). It would seem that having the shutter release button on the lens there would be very inconvenient anyway. You'd have to reach around to the front of the camera and fumble around. Not a good prospect for steady shooting. Assuming that what I'm seeing is correct, it looks like a simple L shaped piece of metal that has a hole in it. The hole looks smaller than a conventional cable release, which is in your favor. What I would do is use a cheap cable release and screw that thing in there snugly. The tapered threads on the cable release should give you a good compression fit. Then run the release end to the top of the camera and attach it there by some simple means, giving you a shutter release in a "normal" location.