BMW sold the 700 in many markets, just about all the European countries, the UK, South Africa, the USA and Canada plus ad hoc deliveries to many more.
They were assembled in Belgium and Italy and in Argentina under licence as a De Carlo.
There is an official BMW Isetta/600/700 “club”, recognised by the International Council of BMW Clubs which has 1,300 members, but the number of 700s on their register is not known.
They organised a drive from Austria to Italy, sort of recreating the process of getting the 600 redesigned into the 700, which was attended by about 30 cars.
There is an unofficial register at https://www.bmw700.ray-vin.com/census/census.htm .
There is a Facebook Group BMW 700 Fans ( https://www.facebook.com/groups/45368477777/ )