Phil -- can't thank you enough for your photos of the disassembly. Just what I was looking for. I think (fingers crossed) that I've got it squared away, though I'll have to wait until tomorrow to see if I did things correctly.
By using the scotch tape method (noted above), I had determined that infinity was really right about 3 meters as indicated on the focusing ring. It got this far out of whack a few years ago, when I had removed the lens assembly to get at the shutter, which seems more or less OK now. As you mentioned in the Flickr series, loosening those brass screws too much leads to big problems since they come out of the clamps. In just trying to get everything back together (a struggle late one work night), I'm sure I paid no attention to lens collimation. The camera itself I sent out to have the shutter worked on, but the repairer never got to it. So after two years, I got it back this week.
Anyway: at first I was thinking I could simply loosen those brass screws (mine are single slotted, unfortunately) and simply turn the focusing ring so that what was 3 meters would now be infinity. (In my defense, I was able to do precisely this with a prewar Nettar recently.) But of course that threw the whole focusing ring off -- near focus stopped somewhere around 1.3m and the infinity stop was well past infinity.
Reading the Flickr text again, I realized it's the front element that has to be turned -- I know: duh. I used a rough justice method by noting that on my camera, the 3 meters setting aligned just about with the umlaut A in the Voigtlander engraving on the lens name ring. So with the loosened focusing ring held at infinity and aligned with the index marking on the DOF ring, I turned the front element clockwise until the A aligned with the infinity and index marking. It should now be in the general ballpark; getting the infinity mark to stay lined up and right at the stop wasn't quite straightforward. But at least I think am doing it right. We'll see what daylight shows, and adjust accordingly.
