I've mentioned it a few times too. Changing a first gen Carrera from Tachy to, say, Deci would have been impractical as it was effectively a new watch, so the buyer would just have ordered the dial they wanted in the first place, but when it is an item as easily changed as a bezel, it's little surprise that we see them turn up with "non-catalogued" bezels occasionally.

I'd sound a slightly cautious note to Paul's "it is correct" though - it may have been the original set-up of that particular watch, but we can be more certain that it is possible and period correct at least.