Unbelievably, I came across a Nikon SS-F2 body the other day. I couldn't believe my eyes to finally see one of these rare creatures. I had only heard about these guys and never knew anyone that had ever physically seen one before.
Apparently these were custom modified bodies used for photographing animation cells. They have a custom gridded focussing screen that is precisely positioned and immovable for exact line up of the images.
The only photo I ever saw of one was on MIR's site and it was a DE-1 finder. This one utilizes a DP-1 finder.
Its in decent shape, but far from mint. The seals all need replacing, 1 sec doesn't retract the mirror (but all other speeds sound to be in the ballpark). There is some gunk on the 2 leading corners of the mirror (not visible thru viewfinder). The meter is jumpy.

I'll be posting it on the bay this weekend and we'll see what the market thinks it is worth. Should be interesting to watch!