I have a Nikon 28mm f/2.8 AI-s to sell. It is near MINT quality. The optics are perfect. No scratch whatsoever. No marks on the body of the lens. I am only the second owner of this lens. The lens was never used without a UV filter. It works perfectly and makes awesome pictures. For more info see the review by Ken Rockwell. Here's a little from the review :
"There is no sharper wide angle lens made by Nikon for SLR cameras, and it is the only Nikon wide angle, along with the 15mm f/3.5, that is completely free from barrel distortion at ordinary distances. Optically this is almost a perfect lens and one of the most perfect lenses you can get to fit a Nikon camera."
Included is a Nikon L1A UV filter and original booklet.
Also, I got a KAWA adapter Nikon to Canon if you are interested that I could give away free. Value of approx. 20$
Asking 300$ including shipping.