Spark plug wire adhesive??? w/pics

[Wishiniwuzfishin]

While doing a spark test on my 1974 115HP Johnson one of the spark plug wire ends pulled out of the coil. They just push onto a metal prong inside the coil but I noticed the one that pulled out was the only one that was missing a little triangle shaped "grommet". It appears some sort of adhesive is used to hold them in place. I pushed the wire back in and spark tested ok. Does anyone have any suggestions on what kind of adhesive I might use to repair it. I have no idea what the part of the coil the adhesive would stick to is made of. Thanks.