Yes, I agree that lots of rust starts just at the lower edge of the window. Removing the window w/gasket, repairing the rust, painting with Rust Encapsulator Black (formerly Corroless, I think...) from Eastwood Company, and painting with the exterior color will stop rust immediately.

I've had the glass out from my '86 twice, and it needs attention again to the spots I ignored before. Bu this time I think I'll drop in the newer tailgate with the flush window. That should prevent water from pooling on the ledge below the window -- because the new t-gate has no ledge.

"...only have a bit of surface rust on the top face of a rocker panel where the paint has rubbed off..."

Pull the seats, peel back the carpet, examine the floorboards. They rust from the inside out. While you have the carpet pulled back, pop the plastic caps from the insides of the rockers and blow out the accumulated crap. You might take the opportunity to spray in some rust inhibitor (also from Eastwood).

I'm sure you can find an equivalent supplier of these products in the UK.


--
Don Foster (near Cape Cod, MA)