Do anybody happen to know if there is a company close to anglesey will to drop off a caravan or small motorhome at the circuit for use during the 24hr.
Haven't asked either of these guys if they'd deliver, but they're based in Conwy and serve/mention Anglesey:
http://www.goexploremotorhomehire.co.uk/
http://www.conwycamperhire.com/
These guys have at least one 'van on Anglesey:
http://www.motorholme.co.uk/motorhomes/wales6.htm
Same here:
http://www.camperbug.co.uk/valarie
Caravans are harder because a lot on Anglesey are statics.