This weekend work... to fix the rust and prevent further rusting.
After removing the plastic refuelling pipe and the clipped breather pipe(tucked away behind the stub of the fuel tank)

As you can see in my previous post, both sides were starting to push the square inspection bungs away from the metal and were allowing water ingress. I cleaned the rust away as best I could with a wire brush and then gave the rusted parts 2 liberal coats of Aqua steel .. something like curust but a slightly thicker consistency.

You can see the extent of the rust inside the sills.. strangely , the bung was worse on the OS but the NS was much worse for rust inside the sill and as you can see on the bottom picture, the paint was starting to bulge the paintwork on the outside.

So after coating with Aqua Steel and letting each coat dry. I cut a piece of plastic to cover the inspection hole and then stuck it into place using a silicone sealant. after letting it dry, I then gave it all a coat of Zinc primer, including all the way up the iner wing.

After that had dried, I gave it two coats of Tetroseal underbody spray.. And determined to protect the area from further dirt and wet I made up a plastic mudguard/inner wing to go all the way over and hopefully protect the inspection area as well as the weld running up the wing. ( I didn't have enough for the NS as that requires a larger area of plastic) You have to be careful here to alow enough room for the wheel when the car is on low.

And lastly I noticed that the paint had started bubbling from the outer sill. Determined to avoid the sill welding fiasco of the silver one I decided to cout away a couple of flaps of paint to reveal the rust, which wasn't really there, but there was some rusty water. I coated the revealed metal with 2 coats of Aqua Steel and then a coat of Tetroseal and folded the flaps back and held them down with tape in the hope that the paint might hold the flaps in place.. that might not work and I'll have to think of something else.. we'll see. With having put the plastic pannels in with sealant, it gives me the option of opening them up again for another treatment or even waxoyling.

I hope this helps someone.