AtBrazilia comes close but dare I say it's custom?

I would say Bitstream Engravers Gothic. It's like Copperplate Gothic Sans

Looks like Gotham to me

I disagree about Gotham. The S isn't flat (wide) enough.
Gotham is quite regularly geometric, wheras this sample is noticeably wider/flatter. True, it could have been graphically widened, but Engravers Gothic already seems like it has the right shape, in my opinion.

Hmm, you're right, Mike: it's not Gotham...

but it's not Engraver's Gothic either. Neither font has an M that descends to the baseline like this M does.

I think this is likely to be something custom, modeled after the classic Chanel logotype. I seem to recall hearing about it, not sure though.

From what I see from many years, in Paris, its a custom all caps only font.

Thx