Morning all,
In this thread there is a copy of the cat-alogue (

re: the 'other' thread) for the 'red'. It gives that the belt is a B60 (the poor copy makes it look like an 'H' but it's a 'B'. This is confirmed by a belt bought for one of mine which was measured from the old one.
There has been a bit of discussion about the belt material best suited for applications like this where the belt does a fair bit of twisting and turning. I'm no expert but I believe Kevlar belts are the go.
Belt can be sourced from a bearing shop or the like.
Hope this helps,
Cheers,