Hi Gwilym,
Thank you very much – I did have a look at Eriks website and probably give them a call as well. However, I've found & ordered belt type Z12.5 with Li=337 from George Lodge (nice thing is that they offer free delivery…) so I'll wait till I'll receive it to if it fits.
And yes, I know about standards for the belts – well in an amateurish way – but this one is a bit of an odd-ball as it is quite small and something between 3V and Z profiles….
Thanks again, have a nice Christmas & Happy NY,
Martin