Nice bike Geoff, brings back great memories for me.
When I was a 13 year old lad (in the early 70's) my Dad bought the remnants of a 1953 M20 (plunger frame) as he wanted the MagDyno on it for spares for another bike (a Velo I think). It was only really an engine and frame, no forks, rusty seat base, no tank, rear hub only but it was too good to break for just the magdyno so I "acquired" it as a project. Took me fully three years even in those days to find all the missing bits and restore it. When finished I was just 17 with only a provisional bike licence but as luck would have it we had an old sidecar chassis lying around which I then restored and with the addition of a large wooden box, I fitted it to the M20.
I then proceeded to ride it around (including to school) on "L" (learner) plates for the next year or so as UKlaw allowed (perhaps still does) you to ride any size motorcycle as a learner before passing your test provided it was fitted with a third wheel ( a sidecar strictly speaking). For a teenager living in the countryside with no public transport it was a great way to get around. With the box on the side I could also take more than one rifle and associated kit to the range and the bike would run on anything, even some sort of aromatic stuff I found in a large drum in the garage!
If I didn't have so many projects on the go I'd be sorely tempted.