After I upgraded to version II I put my 500mm f/4 L at a local shop to sell on commission.
They have had it a few months and I thought I would post a link to their site here to see if I couldn't help them along.
It is in excellent condition, extremely well cared for, AF performance was always the best of any lens I had.

If interested you can see it at this link.

http://www.bakerphotovideo.com/canon...canon-500mm-f4