This is a new one to the comerunity, just come in from Berwick upon Tweed. Customer bought it 2 years ago with very little rust, he's had it resprayed and now sent it down for performance and safety updates, inc. one of Tim's 6 speed boxes
I'm no expert on campers, but it looks very much like an earlier version of the model shown in the Commer Sales Catalogue I posted in the Media section. Did Rootes do their own versions originally or were they outsourced. The smaller raised roof section is the same as the catalogue. This van and the one listed on EBay in here in Australia seem very closely related.
Commer did the Maidstone conversion, very similar, but has round rear corner windows and the roof fabric is concertina. Bluebird superseded this model with the Wayfarer, which had a larger pop top.