I am late to the party on this one, but hey who doesn't have an opinion on what is best for someone else's problem. The time honored tradition is re-threading to Italian for a buggered French bottom bracket. Because the Swiss is 35mm like the French, Would you consider going Italian. You know they share the Alps so it makes just as much sense. You can create a story of the bike being built for an Italian Alpine resident, hence the extremely rare Italian threading. The chance for obtaining a Swiss cup is so slight, if it were I I would go Italian. for all outside appearances it appears the same and yet is more serviceable. It would be more fun to ride than wait wouldn't it? At any rate, in the interest of universal good will, we should keep our eyes open for a Swiss cup for the needy.
john strizek
sacramento california USA