Here is a photo of my 1163 GMT. The bezel is a service bezel, so maybe you are right that these glossy bezels were later service bezels.

What is 100% sure is that this bezel was supplied by Heuer, because I got the bezel from an ex-Heuer watchmaker in Sweden. I am sure a lot of the old timers will remember him, he sold off his parts about 10 years ago. I think his name (or the name of the guy that found the parts) was Anders - I am not sure. I can remember that Par Wallstrom, one of the original guys on the forum had a contact with him, and the parts were all genuine. This bezel came from his parts and was certainly Heuer supplied. I would imagine it was made in the 70s or early 80s and supplied by Heuer to watchmakers at that time. I have not seen this type of bezel coming out of TAG-Heuer in the last 10 years, so I guess they ran out of stock as well. I think it looks cool as the "pepsi" look has an historic link with the original screwback Autavia GMT and the later 2446C as well.

You should also not confuse this bezel with an almost identical bezel which came on the Bel Air GMT (pictured below). The Bel Air GMT bezel was probably made by the same parts manufacturer Heuer used, but it is a different bezel and different insert - the diameter of the Bel Air bezel insert is appreciably bigger than an Autavia 1163 one. It's actually easy to see - you can see there is more space between the numeral and the edge of the bezel on the Bel Air, whereas on the Autavia the numeral goes almost to the edge of the bezel. Also the solid metal part of the bezel is also shaped differently.

Here is the Bel Air, a very cool watch, and probably the GMT Heuer would have made if they decided to use Valj 72 rather than a Cal 11 for their GMT. I don't think I'd classify it as a "Poor Mans Heuer" as the case is different to the Autavia case - Heuer never made a val72 in the modern Autavia case style….maybe a shame...