Good luck, personally I would have given it a good clean and oily ragged it, it looks a good find.
those speedo drives come in left and right handed work out what rotation your speedo need.
you will also find they can be staggeringly expensive £75 quid is not uncommon.
Most common source are ex WD stocks so if you used 16H or M20 where you are that might be a start.
Have you considered an electonic cycle speedo? lots of vintage bikes here are using them as a way of keeping inside speed limits.
Ther eis such a thing as the British two stroke club you will find helpful.
Meetens
http://www.meetens.co.uk are the go to place for Villiers spares, they have everything.