It looks to be a typical early 1970s G3 carb 125cc with zip start. Very common at the time. That base is where I'm at a dead end. It looks similar to the Mayfair low arch bases but with unique moulding. Those 125s are a gem when it comes to longevity and smoothness. Better than the 160 in those respects.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!