The feedback from 3M:
"we recommend using the manufacturers adhesive, but 3M 08116 Panel Bonding Adhesive would be a secondary choice."
I have the bonding adhesive, and 3M Bondo 932 Self Adhesive Patch, and am just waiting for the temp+humidity to be a bit more stable for curing.
I'll take pics to show the success (or failure) of "Plan B".