Hi, I recently purchased an Argus C-Four that slips occasionally during focusing. I need to reset it correctly to Infinity and don't know if I should take off the lens, or pop the top off to reset it? Of course before I do that I'm wondering is there any hope in getting the gears not to slip? I've scoured everywhere but only finding some info on Matt's Classic Cameras on his rangefinder being loose that was causing it. I don't see that on mine. Would lubrication fix it? Thanks!