Originally Posted by
TejanoTrackie
If it's early 1970s, then rear dropout spacing is probably 120mm, which is approximately 4-3/4" and is the same as a track wheel. Front fork is going to be 100mm, and is the same for track (nutted) wheels. Also, original wheels were 27", so the brakes will need to have about 4mm more reach to work with 700c.
Front fork spacing on seventies UO/AOs is 96mm. In general, added reach is too much on that model for even the stock Mafacs, which have considerable reach. There is some variation from year to year, however. I would check brake reach on another wheel first. Rear drop spacing on this model varies, from 120-@125.
I would build your own wheel. It's what I did on my UO.