Most of the work up till now has been getting the vehicle in some sort of order, tempting though it was to go straight into the motorhome conversion work. I've replaced the timing belt, front crank seal, a lot of brake parts and various smaller jobs ..... and lots of welding. A quick measurement of how much welding showed that I put down about 10 metres. Thinking about it, I should have replaced the floor entirely as welding round the perimeter would have taken less than that. OK, the new floor would have needed stitching to the chassis members the same way as the old one was spot welded in order to keep the integrity of the structure, but I would have ended up with a brand new floor instead of a patched one. Something to think about if anyone else has had the tinworm run amok.
The sides have been insulated with 50mm foam slabs which were cut to fit between the ribs. Awkward bits such as round the fuel filler pipe were stuffed with mineral wool insulation taken from the caravan, and the edges of the ribs had strips of wood floor underlay 3mm foam stuck to them so that the insulation isn't bridged. I'm now waiting for the varnish to dry on the 5mm ply sides so I can fit them.