Thanks for all the great suggestions I've had here.
I've been working my way through them.
All of the established hauliers mentioned here won't touch it, either due to length or the fact that it's a one-off.
The 'list your item and see' websites are interesting, I've tried them ...
http://www.shiply.com/search.php (and even as I type this, I've received an offer and a private query!)
I've also contacted one or two man-woman-with-van services and am waiting on quotes.
My guess is that when I eventually find someone willing to lug my boat to John O'Groats, it won't be cheap - I can live with this, I would normally have splashed on a plane flight to somewhere with exotic WW at this time of year. To save my hard-earned wealth going to someone random - if there are any paddlers out there needing a petrol-paid trip to the far north, with spending money thrown in? Seriously, make me an offer.
Cheers,