Shoe Goop works well on most leather products. Make sure you degrease the surface where it will go first.
Silicone would work for that.
100 % silicone would work.
Silicone or epoxy will work .
Epoxy or silicone will both work.
Silicone is best for that.
Silicone would work.
With a silicone or silicone based glue such as Goop or E 6000.
Silicone or silicone based glue will stick to almost everything.
Try a silicone adhesive, such as Devcon. This adhered well to a %100 soft silicone rubber part I needed to glue onto some insoles.
Gorilla glueANS 2 - Epoxy will work and silicone will work.
Elmer's Glass glue would work, but I'd recommend taping the back too.
Super glue won't stick to silicone.