Two really nice discoveries were
1)
Power brakes and front discs
There's (currently at the time of posting) a kit sold for this retailing at about 1300 euros
(I'm sure you could find cheaper solutions but this is in my opinion is a really nice upgrade)
2)
This car is ahead of the times
It is a plug-in hybrid!
EDIT:-
3)
Someone has also installed electronic ignition of some sort or other so I don't have to play with points. That's also quite a nice upgrade to have don't ya think?