Hello, I started, just for fun, in converting polaroid 110 or similari models to pack film. (one pinhole and one finished 110). at the moment I'm building an integral film back on my own and so on... but with the integralback I first have to use another lens, not the rodenstock (distance lense-back becomes bigger)... my question is, where do I get lenses and or shutter except old cameras? and if this is the only possibilty, which cameras to destroy

thx and happy building