Ok, so a friend picked up a c-four at a garage sale for like 20 bucks, she came up to me and said "here figure it out." So this is where I am now. first question: can you swap out the lens with other lenses? I figred out how to take the lens off (its hard putting it back on), and it clearly looks like you can swap it. Next, I figred out that the range finder is messed up, does anyone know if this is something fixable by an inexperianced camera fixer? And lastly, there are two screws underneath the wind knob, is there any special way to get them out, because they are not moving with a screwdriver.