Stan, I do not think that it will be worth it, as that rangefinder is not at all expensive. That Petri does develop a wobble and I cannot remember how I dealt with mine a few years back, but there might be a ring around the rear element, in the back of the camera. You might see if one of the two indentations on that ring allow it to move easily by using a tiny screwdriver. If so, simply tighten that ring by turning it carefully.
Of, alternatively, under the logo ring, there might be screws that need tightening. This is not a major problem and I have done this sort of thing rather easily in the past. The logo ring should screw off normally (ie, counter-clockwise). I wish I could be definitive here, but this was long ago. - David Lyga