$400 · MINT Pentax 400mm f5.6 super telephoto lens - adapt to digital / mirrorless

Downsizing my collection, and reluctantly putting up this rare supertelephoto lens. It's an Asahi Pentax 400mm f5.6 lens in absolutely gorgeous condition. The glass is 10/10 (free of mold, scratches, fungus, etc), the aperture blades are clean with no oil, and the body is a 9.5/10 (almost zero signs of use), focus is smooth, aperture clicks are well-defined. Everything looks and feels new. Some cool things about this lens: - Adapted to Olympus or Panasonic it is the equivalent of 800mm, adapted to Canon, Fuji, Nikon, Pentax, or Sony APS-C bodies it's 640mm. TONS of reach for sports or wildlife. - It has 12 curved aperture blades for beautiful bokeh (background blur) - Has a built-in retractable hood - Has a built-in tripod collar that can be rotated 360* - M42 mount (with a $10 adapter it can be made to work on Canon, Nikon, Sony, Fuji, m4/3, Olympus, Panasonic, or Pentax...can be seen working on my Panasonic micro 4/3 body) Comes with the following: - Case (the top is missing, but I was only using it to store the lens in) - Original Asahi Pentax UV filter with original case - Two original metal Asahi Pentax front caps - Rear cap The last two photos were taken with this lens on an Olympus OM-D E-M5. Please note, this is a film-era lens, and has manual focus and aperture. If you have any questions, please feel free to message me. I *MAY* be interested in some Fuji or Micro 4/3 stuff for trade (Olympus/Panasonic) with some cash in either direction. (Mostly interested in a 12mm f2.0, or a 16MP body with a lens).