Hey Graham,
Congrats on your new GL1500! You are STILL welcome to hang around, we won't mind! The lesson to be learned, and to be carried over to your NEW GL1500 is "if you can't get Ethanol free gas in the UK, then you need to treat that gas with Sea Foam or other additive to keep the Petrol from separating from the Alcohol". Those Honda Carbs. are a bit trickier to get unstuck then the Yamaha Carbs.
Good luck with your new scoot,
Earl