I should start but saying I don't know what the answer is but I know superglue dries too brittle and the spirit gum dries too soft.
You need a clear glue that dries firm but 'rubbery' like a clear silicone.
You could cause more damage experimenting.
You might have to bite the bullet and go for the HD stuff.

Hopefully someone will have a better suggestion but thank you for the link to that site.
They seem to have a huge range of products.
Have you thought of contacting them directly and asking them for suggestions?