For reference, yesterday I completed focus adjust of Ishpuini's lens. Here is how to do it:
repair Pentax 28mm lens Disclai - pentaxke | ello
So adjusting infinity focus is not done with spacers/shims (that was a first for me.) It's not for the fain of heart, but with a little of perseverance and patience it is a pretty straight forward adjust (only that Wim's lens clearly has fallen and that adjusting focus meant that the rear part of the optical group interfered with the gelatine filter holder and made shifting near impossible. I resorted moving this holder to the back with 4 little shims. That part is not included because it was specific to Wim's lens.
If any questions, please ask!