Just scored one of these on the Devil's Junkyard. Looks to be in good condition, the expected misty glow wide open and very decent levels of sharpness fully kicking in by f/2. Somewhat disappointing closest focus distance at 0.6m, and the expected tricky focussing - LV with magnification is very definitely your friend with this lens. There don't seem to be any examples using a K-1, so here goes.
First few tries, all SOOC JPEGs, at f/1.2 unless stated otherwise:
Not the greatest image ever, but just look at those bubbles!
Comparison of f/2 and f/1.2:
Saving the best (?) until last. Some PF if you look closely, but the edges and corners look nice to me:
Flickr