My father was in the 2nd Paratroopers and said these things were usually chucked out far away from the drop zone so they didn't have to bother with them. Might be useful to have in the boot of your car in case of a breakdown but these days an electric scooter would be better.
Post war in london I would often see those Wellbikes being used for go to work transport.
were they Wellbikes or Korgi's that was also a folding motorbike. incidentally a few years ago (maybe 20) there was an Italian folding motor scooter aimed at yachties called a DeBlasi, didn't survive long in the market place