Thanks chaps, plenty of food for thought.
I got the idea watching some Scottish - American folk thing on BBC4, one of the bassists was using what looked like a Godin (or something similiar) fretless electro-acoustic. Interesting sound, not quite stand up bass but with the something of that quality about, very woody with an element of er, slappiness about it. Be interesting to know how he had it tuned. The Dean is a full 34" scale so I've got a bit to play with on that front, although it'll only take a medium guage set of strings at most.
Might see if Vince Hockey is still trading down in Southampton. Might be a job for a luthier after all.