Which surprised me. (and means the bonus game doesn't work.)

So-according to a Heuer/Enicar expert and via a font of Heuer knowledge, Heuer put together V72 movements for Enicar so it is feasible these were leftover and put into Heuers, along with a bespoke bridge. (no, I don't know why a regular Heuer bridge wasn't used!)

Here they are for comparison-

There is at least 1 Carrera example known with the same movement. Any more known?

Interesting, huh?
Steve