Hi Pirie,
Great to hear of someone getting an MX1 race-prepped when there's all this talk on the forum of those pesky CZs being 'the holy grail'! If you haven't got one already get on to Frank Conley (his name's all over the web) and order a copy of the MX1/2/3 parts list. Folding pegs were listed as an option on the MX3 (same frame) and my guess is that Frank will have the parts you need on the shelf. My recommendation though would NOT be to go down this route, especially for a serious race bike. By modern standards the pegs are way to narrow. Buy yourself a set of modern universal wide pegs and get a local fabricator to weld some mounts to your footrest hangers. Cheaper and far more effective solution. If you don't want to irreversibly damage your original hangers then get your man to make something up, it's not exactly a complicated setup, and it all just bolts to the main frame.