I am not sure where you could mail order furrule glue in the UK, but
here is a website from the colonies:
http://store.yahoo.com/gear-west/exelglue.html
If you check this web site you can at least get a image of what it
looks like. (It looks like a can with glue).

I bought a can of exel furrule glue 20 or so years ago and it does not
take much to glue ski basket/furrules to the sticks. As mentioned, the
glue that remains on the stick when removing and replacing baskets is
usually adequate for the new basket.

Ski shops that sell roller skis are likely to have a supply of furrule
glue. If you cannot find a supplier in the UK (mail order or
otherwise) it may be a good time to go on a ski holiday in Norway.

Edgar