I just replaced the bezel insert on a GMT Master II (with the correct hand stack) that I just got from Andrew. I used Elmer's Stix-All. It's clear, heat and water resistant and flexible. It takes 24 hours to cure completely, so I could glue it with the bezel off, check it and adjust as necessary. The down side is is that it takes 3 days to cure completely and I wanted to wear the watch. I'm very happy with the results.
Scott
PS the dial is much improved over the one pictured on Andrew's website. The R*lex and crown are the correct size and spacing and the II is with serif, so the dial looks pretty good. The bezel was the only big drawback to my eyes.
S