the omega calibre 321 see photo has the bent index pins-easier to adjust. the rolex /valjoux calibre 722-1/72b has the spring for protecting the hairspring-part no 6610b both are designed by the ebauche manufacturer valjoux and lemania and not an after thought by rolex and omega to upgrade etc.
competition of that era-very similar-even have the same casemaker.with a 13'''valjoux movement. like for like the rolex's are about 12 times the price-now.but are they better? who runs a chronograph for twelve hours?
universal geneva-compax-1955-calibre 281-(with dust cover) case made by-C.R.SPILLMANN &CO LA CHAUX DE FONDS (11/7/34-5/4/88) who also made these waterproof cases for ROLEX and many others of that era 2 part case with screwdown caseback and round pushers-hesalite armoured glass. CALIBRE 281 (photo be