Thanks for the reply rob
As you mentioned, they do seem to be difficult to come by; I have had a look at the Scarlatti website, the product is good and well priced but you have to factor in the additional costs for the base unit which they cannot supply. Starting to toy with the idea of stripping the pillion seat cover off and modifying that base unit to fit the Scarlatti hump to.
I'm currently trying to convince someone to part with theirs, so we'll see how that goes first
Cheers