Footboard rubber mat glue
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
Thanks to George Dockray and Mark Etheridge of Moto Guzzi Classics for providing this information on the old Yahoo! Loopframe_Guzzi news group (which has now moved to Groups.io). In their own words...
For this kind of stuff I use 3M 1300L contact adhesive. It's what you use for bonding de-ice boots onto the leading edges of airplanes as well as the heated boots onto the leading edges of propellers. You need to follow the application instructions carefully.
Mark Etheridge of Moto Guzzi Classics:
Best to buy the metal reinforced rubber ones from me and use 3M weatherstrip adhesive (08011), no more lifting or curling even if gas gets on them. The plain rubber ones are a constant pain, no matter what kind of boogers ya put on them.