I'm trying to collect parts for a homemade camera and am need of a medium format lens. More specifically I'm looking for the barrel/focusing mechanism/helicoid part of the lens, so the condition of the glass is not very important to me since it'll likely get discarded.

If anyone has any moldy, fungus infected, and/or damaged lenses you're looking to get rid of for free or cheap, please let me know!

Thanks!