I bought a set of VO's own 45mm fenders to put on daughter's '87 Miyata mixte, and no amount of bending was going to get them to fit on the rear, and especially at the chainstays. Some judicious metal cutting might have done the trick but I didn't see that working out well. Sharp edges, weaker fender (the edges are doubled over), and so on.

I think 37mm fenders would have worked on the bike and as the current 1 1/4" tires are only 28mm wide they would have been almost wide enough to cover the tires by the 10-12mm extra width VO recommends. YMMV of course, but measure all the clearances, frame as well as around the tire.

Of course VO can't imagine every possible frame/tire situation, but now I have a pair of fenders that can't be returned because I tried to make them fit. I'm sure they'll fit some other bike down the line though.