Contact cement should work.
Read the can VERY well (it is extremely flammable).
Clean both items to be glued.
Coat each side (gasket and slide) with the glue and LET DRY!
VERY IMPORTANT STEP.
When comletely dry to the touch; Stick the gasket to the slide.
IT WILL INSTANT BOND. MAKE SURE its where ya want it!
Contact cement is waterproof when dry.
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW