Thanks for the welcome everyone.
Enjoying my zed and have already decided that the first Winter task is to replace the sills.
Found a brilliant article on how to remove & refit on the forum and it doesn't look too difficult even for me.
My sills have rusted at both ends on the underside next to the wheels - i took the inner arch liners out and removed a pile of dirt. I will tart them up meantime best i can, but ideally will replace later in the year, as they are not too noticeable unless you get down & look.
I have searched the forum and found a couple of threads about purchasing new sills at £150+ each from dealers, but also mention of fibreglass option - does anyone know of any fibreglass/plastic options available, or any other supplier of new parts other than the dealers?