Re:
Thanks both for your responses, I should have given a bit more detail! Reach is about 60mm front and back. And with regards to quality, the bike is mostly shimano 600 so some brakes of a similar quality is what I’m after.
The conversion is new to me thanks for sharing! I have seen shimano do some BR-R451s that I could use the conversions on, which might be a good option if nothing vintage pops up