Purple stuff

Thanks for the link! I took some measurements:
BB clearance with 23c tyres is 272mm. Width between fork blades at 320mm from the middle of the dropouts is 43mm and the brake reach is less than 70mm with the 18mm increase in brake reach factored in. I guess that makes it a suitable candidate. Two things are not ideal though, no mudguard eyelets at the rear and only one pair of bottle cage bosses at the downtube but I think I can live with that. I won't be starting the project in the near future though since I have a couple other projects that need to be finished first. But it's good to know that the Diamond is a suitable candidate since I was thinking about selling it for the sake of diversifying my stable. If I convert it to 650b I have a good reason to keep it other than my general reluctance to part with things I feel attached to.