I did not fly on Maggies's trip but did some of the 'trials' with the 'VIP' cabin. IIRC it was an ordinary (secondhand ?) touring caravan and there were a few problems. Finding somewhere to attach the chains to it tie it down to meet the regs was one. Another was the tendency for the caravan walls to dance to the tune of the Allison and Hamilton band. Soundproofing of a sort was fitted. Another was the way it got hot inside. On the C130 the heating was supplied via overhead vents and this heated up the caravan. Fans were installed but they were nosy etc.
As for Denis watching the refuel, I never knew a pax who did not if they got the chance. !