From Collectible Cameras I scored a black barrel Nikon 135mm f3.5 for my Nikon S2. The lens came with a Nikon skylight filter, the original lens caps, front and rear, the original clip on lens hood, leather case, extra leather strap for the case, the auxiliary finder and its little case - all in essentially new condition! Lovely stuff. The aux finder is rather like looking down a rectangular tube, but it does have parallax compensation. I think it can best be used with both eyes open. Some variant of the Mighty Kontur finder would be ideal here!
Now if I can find a 35mm or a 28mm at a reasonable price! They seem to be really costly. With a 28 or 35, the 50mm 1.4 and the 135 I'll have a nice outfit.