Couple thoughts:
a) I have used 3M structural adhesive that uses a regular caulk gun (not a special gun). If you are convinced you want to glue them you might try that.
b) Aren't there any mechanical attachments on the bezel/backup light? I re-installed the parking lights on my glass front bumper by making a small bracket and bolting them in just like they were originally. I'd rather have them screwed in than glued....
You can disregard the damage here (which has since been fixed) but posting this to show the parking light/concept (note that the parking light stayed in place - LOL!):
K
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'63 LeMans Convertible
'63 Grand Prix
'65 GTO - original, unrestored, Dad was original owner, 5000 original mile Royal Pontiac factory racer
'74 Chevelle - original owner, 9.56 @ 139 mph best
http://www.superchevy.com/features/s...hevy-chevelle/
My Pontiac Story: http://forums.maxperformanceinc.com/...d.php?t=560524
"Intro from an old Assembly Plant Guy":http://67-72chevytrucks.com/vboard/s...d.php?t=342926