Your mystery bike looks like an alternator B33 fittted with a Gol Star top end ( OR OTHER WAY ROUND ) .
The thing on the end of the timing cover will be an inductive pick up for a wasted spark ignition.
These breathe throuhg the timing cover so the tube at the top is the breather.
having fitted an alternator & inductive EI there is no need for the magdyno which has been removed and the uneeded section of the timing cover cut short.
Quite a nice piece of handiwork.
I do not think their was ever an alternator GS but I am sure some one will correct me if that is wrong.
Without the maggy drive there is nothing to drive a chronometric tacho so it looks like he has turned an old tacho case into a dash panel
Thanks for sharing.
M20's are a little thin on the ground in the USA but there is currently a bogy bobber on eBay
at a reasonable price.
Just remember that the smaller slower bikes are not particularly suited to modern city traffic.
My m20 will sit on 70 mph all day but push it much over that & you pay for it big time so not really suited for transcontinential runs.