Hi again,
You've given enough info to go on with so I'll start boring you with it all.
It has 148cc motor, not a 147. This is important. Although both were made by Villiers they are quite different and C/E used both. Yours has a Mk XII-C motor introduced in 1931 & will cruise about 35-40mph, flat strap about 50ish. Eats hills.
The C/E was one of the better quality prewar two -strokes and well made. You will be able to get a copy of their 'Book of Service' from the VMCC library, it is open to the general public. It is about 50 pages and has everything you need to know.
Join the British Two-stroke Club and/or the VMCC. They will welcome you with open arms. Like all old bikes there are traps for new players but nothing serious or expensive. Villiers engines have an undeserved poor reputation. When sorted out they are very, very good.
I don't know where you would buy inverted levers in England, I'm in Oz.
Cheers, Bob
