Null,
your recollections are spot on. I think by then the VIP Andover had departed although it was on 48's 'books' as FEAF Comms Flt had disbanded. Thankfully I was too lowly for such a prestigious task ! As I recall the poly sheeting had a not unexpected consequence. It may have lessened the chance of a hydraulic drip on the pax but it allowed the humid air to condense and drip water into the cargo compartment in rather greater amounts than normal.
Shortly after that I went home to the UK.