Here is the only official reference picture of an 1163 Autavia i have seen, its in a 1972 Heuer catalog http://www.onthedash.com/Guide/_Catalogs/1972_Chronograph_Catalog/72Chronos1213.jpg
As we have speculated in the past a buyer back then could opt for any of the bezel choices when they purchased their watch, it is perfectly reasonable to think someone chose that decomp bezel on your watch ( i think you are referring to a Siffert model when you say Joe ). Then there is also the possibilty that someone has replaced the bezel inner with a genuine part some time at a later point. As always a picture would be nice for us to help you with it.

Here's my diver version with the bezel in place

Cheers - Darren

: Good Morning Heuer Fans...

: What are your thoughts on the Decompression Bezel?? And why so
: few?? I very seldom see anyone talking about this subject and
: even fewer up for sale...

: Personally I like this bezel better then the MH or T... The
: decompression bezel is much cleaner, less complicated and much
: easier to look at... Is this bezel rare becasue it was only used
: on the two different versions or was it not offered on other
: models?? The reason I bring this subject up is becasue the Joe I
: pick up over the holiday has the decompression bezel and I'm
: wondering if I should replace it or keep it?? As mentioned
: personally I like better but really want the Joe to be original
: as possiable...

: The red triangle at the 12 reminds me of the Rolex 6538 (I also
: think the 6536) which had the same red triangle, it really
: stands out on the black bezel....

: Thoughts and comments???