Rumour has it that once upon a time the Gazelle frames did not come in the ever confusing AA, AB, and BB variation.
I have a 'Gazelle Champion' (no mention of Mondial). Full SR, derailleur says 74 and could very well be the original. Is made of 531, has the butterfly brake stay and roto BB (with the small butterfly behind the BB).
Was it then back in the mid 70s that there where no other variations (Mondial, AA, AB, BB,...)