I think it most likely was some Jack Wieber's bottling. It makes sense given that the event was in Zurich and the exhibitors were a mixture of Scottish and German.
It also adds up that I thought it was "Jack something" on the label, and that Jack Wieber's have their own labels (and possibly bottles) which would explain why it didn't look like a Laphroaig bottle.
Which also probably means that it's not something I'll come across easily.
I may well get in contact with them directly.
Thanks for all your help.