Reviving a very old thread. In a box of junk I found a Wollensak Velostigmat 3 1/2" Focus Series VII f 3.5 No. 452XXX. It has a purplish sheen and a whiteish/yellowish paint dot above the word Series. It's in a Betax 2 shutter. Maybe a wartime military lens? I'll make a lensboard and take a look at coverage on my 4x5.