I did not know this lens existed until i came cross one on eBay. Searching there find's 3 for sale right now. I love the Olive Drab color, gives it a nice military feel.
Format: 35mm SLR
Focusing: Manual Focus (MF)
Lens mounts: Canon EF, EF-S, Nikon F (FX, DX), Pentax K
First year of production: 1987
Last year of production: 1992
Optical design: 17 elements in 12 groups
An article with photos: http://blog.danielbridge.co.uk/2014/01/sigma-350-1200mm-lens-pentax-pk-fit.html
Format: 35mm SLR
Focusing: Manual Focus (MF)
Lens mounts: Canon EF, EF-S, Nikon F (FX, DX), Pentax K
First year of production: 1987
Last year of production: 1992
Optical design: 17 elements in 12 groups
An article with photos: http://blog.danielbridge.co.uk/2014/01/sigma-350-1200mm-lens-pentax-pk-fit.html