sorry digging up old threads but you pm'd me about tubes
These tubes are hayplon and require special glue. I'm not familiar with products Snip is talking about
Go to westmarine they have a entire section devoted inflatable boats.
They have products to paint or resikin and two part glues for rub rails and accessories
This is from the 1993 shop manual.
Inflate the tube to 2 PSI
Sand down the area of the rub rail with 80 grit paper don't sand down to threads. MEK solvent the area let it dry
use 2 part glue coat one thin layer on the tube let it dry then layer on the tube layer on the rail and stick PUSH HARD.
Patches low pressure gluing
Accessories like rails, grab handles, oar locks HIGH Pressure.