ETX125 dust cap stuck / telescope repair in Edinburgh?

Hello All,

After years of using my trusty ETX125 without major problem, last
week-end, I didn't close the carry box properly and when I picked it up,
it opened and the telescope fell down (from maybe 1 or 2 feet high). No
obvious external damage, but after that, impossible to unscrew the dust
cap! I search the web for tips, found some on the Weasner's website -
ice on cap - but not working.
So,first question: any tips for unscrewing a stuck cap? A friend is
stopping by tonight and we might succeed with 4 hands, but if not...
Secondly: if I don't succeed or if I noticed internal damage, do you
know where I could bring it for repair? Yellow pages don't seem to help
much...
Many thanks for any tips or infos!

Gogo