How about a mint M6 TTL .85 in black. strap. plastic case, manual, no outside box. You mention you want a 28, but the .85 doesn't have framelines for 28. That might bother you. I just use the whole viewfinder with the 28.
28mm 2.8 8mm is in nearly new condition with packaging, instruction booklet, leather case, lens shade, and front and rear caps. Made in Germany. #3608617
Also have a 75/1.4 and a 90/2.0 Asph...
Need to fund some gears and lockers!