Thanks for the additional info Tony, that is very helpful!
I am on Motobins website and can see the switch. I do appear to have a mix/match assortment of levers, they are different from each other.
It would seem I have some up to 1980 parts and then some later 81 on parts. The Bike was manufactured January 7th 1981, so maybe some older parts were available from the bin or else the PO fitted them?
Anyway, I continue on. I have found an excellent company in the UK who are going to try and replicate the graphics on both sides as mine have faded badly, I post up as soon as I have them finished.