I'm no expert on the screwback 2446's, I've only handled a 2 register 3646, but the bezel certainly looks correct. Here is a link to Noodias 2446, I know it's a compressor case, but have a good look at the bezel...
http://m.flickr.com/#/photos/noodia/6862647855/
I'm not saying yours is from a C case, I'm pretty sure the screwbacks had an Hour insert too.
In fact, have a look here too: http://www.onthedash.com/Guide/_Chronographs/62.Autavia/a.Manual--Screw-Back_Case/2nd_Execution_Screw-Back_Case/2446_Second_Case_Third_Dial/

Looks the same, maybe your acrylic is a replacement, which emphasises the gap between the insert??

Stewart

: Hi Stewart,

: Thanks for this. Mine has the screw back and not the compression
: back!

: What do you think of the bezel insert? Any chance it's a correct
: Heuer one?

: Cheers,
: Foxy