Charlie, Here is my opinion based on experience. Way back in the early '80s, I purchased a repro medallion that came with an epoxy mix to affix the medallion. I installed it using the mix, and about a year later, I noticed the medallion was missing. It evidently fell out while driving, or someone stole it. After finding another repro medallion, I decided to go with RTV silicone as a glue to hold it in. The medallion has been in place for 18 years now and firmly in place. I like the RTV because it provides a cushion between the bezel and the plastic, to hold well even under vibration. Also, the RTV won't attack the painted back of the medallion. Bob J [Non-text portions of this message have been removed]