@coatesy, those mounts on the Marzocchi were for Formula brakes, and back then the standards hadn’t really taken hold so makes sense that Italian fork fits Italian brake, but those forks can still take a rim brake, as that’s what most of them used at the time anyway as it was very rare to ever see any off the pro-circuit with the Forumlas fitted.
Chainring BCD is a pet hate of mine, not because you can’t get them, but because they make it un-necessarily annoying finding the right ones.
BTW, 5 bolt 94BCD chainrings are still readily available from Middleburn, TA, Stronglight and others, I’ve still got 5 or 6 94BCD chainsets in regular use and no trouble getting rings for them.