When I was about 12~13 'we' (our little gang) got Vellocette MAC that had been in 'storage' (dumped in a coal shed) for about 30 years.
There was also a BSA C10L with it
Well, 'we' got them going and learned a bit about AMAL carbs, Dowty 'oiliomatic' forks, plunger suspension and running old side valve motors on paraffin (the BSA)
After the owner found out they were runners, he wanted them back and donated them to local tech (probably something else going on?)
My father had a complete running Ariel NH he 'sold' us for ten bob and great fun was had by all
I worked on a different NH probably 30 years later, wish we had known just how stupid prices would get.