Where there's a will, there's a way. If it's decent Moto with nice Reynolds 531 like Grand Record or Le Champion then I'd put the effort into doing the swap and the needed parts to convert it. You could run Tektro long reach calipers. What about running the cups that are in it and then picking up the correct length spindle for the Mirages cranks? I don't mess around with loose ball bb's or square taper spindles anymore. YOu could run one of the Velo Orange threadless bb's. Just depends how anal you are about using a JIS spindle with Campy arms. It'll work but technically your not supposed to. I say fooey!