With a few hours to spare I managed to not sit in front of the TV and instead got myself into the garage. Although I wasn't in the mood for getting covered in rust I did manage to get the van out into the sun for a good clearout. That was after I pumped up the rear tyre with a cheap bike pump (not recommended for those with a heart condition). 
After a struggle drilling off a few rusty screws heads I was able to removed the rear pop outs to unearth some tiny pinhole rust spots in the gutter. I then cleared out the remaining interior, attachments, wires, insulation, gas pipes and old coppers (coins not Policemen) to get a good assessment of the whole cargo bay.
The 4 or 5 holes in the corrugated floor had not got any bigger than the first time I found them years ago, but the struts and floor supports I could see through these holes are looking very corroded. I brought a floor repair panel, but the idea of seam welding corrugation doesn't sound too good and could take a while.
