@gelehu: Oh, and yes, incoming cadence shouldn't matter to trigger 1a2 ringing. But what people would expect to hear from the the regenerated ringing on the 1a2 phones in an EU environment would probably be their local telco's ring cadence they're already used to, i.e. that double-ring thing as an example.
So I was wondering if 1a2 had such an option, but sounds like not, if 1a2 was a US thing only. I'm sure one "could" fit the interrupter with a different pattern of notches for the rotating gear that handles ringing, but it sounds like that wouldn't have been an option if 1a2 wasn't deployed world wide. Apparently different countries used entirely different equipment, with the few exceptions Sam noted (embassies).
Certainly EU phones I saw while traveling in the 70's and 80's didn't look anything like the Henry Dreyfuss design (model 500) that became the default in the US from the early 1950's onward.
