Martyn
I quote below from an email sent by Dixon Bate in response to my extensive telephone enquiry – they were initially reluctant to quote, thinking the Wayfarer was heavier than it really is!
Dear Dr Maynard
I have checked on the unlaiden weight of the road trailer with rollers and it comes out at 70kg.
I have attached a photo of the said trailer for you to mull over.
The road trailer with rollers costs £457.89 inc vat
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Gareth Meyer
B. Dixon-Bate Ltd, Unit 45, First Avenue,
Deeside Industrial Park, Deeside, Flintshire, CH5 2LG
( Tel +44 (0)1244 288925
6 Fax +44 (0)1244 288462+ Email gareth.meyer@dixonbate.co.uk
Web http://www.dixonbate.co.uk/
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and the picture: 
regards
David