John, as Ken says you aren't alone.
If you put the paper/card down and identify the leak (which it definitely sounds like), then there's plenty of time to sort.
If not, then we can go over your fuel piping on the 27th.
I've got some 8mm id hose that i'll bring with me along with the red/yellow flexi fuel pipe originally supplied by RH.
We'll check from the filler cap to the carbs, but if I remember you have the original filler cap.
A simple check, it might be worth checking that you have a seal around the filler cap.
Al