In article , joe-b@dircon.co.uk says...
>In article <50dj8r$4ip@newsstand.cit.cornell.edu>, Bob Neuman
> writes:

>>>More than a few years ago I bought a Cosina 100-500, f5.6/8 zoom lens
>>>that has paid for itself many times over. As heavy and slow as it
>>>is, I wish I could buy another one just like it.

>>Hmmm, it is surprisingly good, but I have been thinking of selling
>>mine, since I don't use it.... Near mint, Nikon Mount.

>Very interesting. Any idea of which other mounts it came in?

I think it came in most popular MF camera mounts of the time.
BTW, it is rather large, and VERY slow - and it isn't too exciting
for color slide work, but it is fine for work with negative films,
being quite sharp with them from 100mm to a bit over 400mm, and OK
at 500mm. The lens does have a tendency to repeat bright lights
in the image at some FL's.
Hope This Helps