there's only 2 sizes really, 3/8" Imperial (about 9.4mm) and metric (9mm dead). 9mm fit french, italian and other continental cranks and milremo is a continental maker so a 9mm pin (from almost all LBS) should do. If it falls straight through the hole then the crank is imperial sized (even though it's a french company) so you need an imperial 3/8" pin. the correct pin probably won't go through easily first time as cotters are designed to be filed to fit and will still need to be twatted pretty hard to settle it in place, best of luck
there's only 2 sizes really, 3/8" Imperial (about 9.4mm) and metric (9mm dead). 9mm fit french, italian and other continental cranks and milremo is a continental maker so a 9mm pin (from almost all LBS) should do. If it falls straight through the hole then the crank is imperial sized (even though it's a french company) so you need an imperial 3/8" pin. the correct pin probably won't go through easily first time as cotters are designed to be filed to fit and will still need to be twatted pretty hard to settle it in place, best of luck