I have learnt something new today. That is yet another alloy thumb latch catcher hi arch base mould I didn't know about.
I assumed the VC125 mark III just used the Mustang/Sports base with the visible step and holes on the arch for the Mustang cowl, fitted with nylon bearing wheels.
The Ebay one shown has had a 160 with G4/LM carburettor set up in place of it's original 125 with G3 carb.
Ball bearing wheels have been added too.
CyberJack, are you saying that the VC125 mark III model effectively took over from the Impala 2 or did a VC 125 with this exact same base and engine cover sell concurrently with the I2?
The intrigue thickens!

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