rusty ruby

[12jslater]

I have finally got myself a mk2 ruby, after sorting the rear window issue noticed the metal looking "odd" beneath the thick red oxide paint, and where the inner wing meets the body is totally rotten, should I patch it or buy a whole new repair panel, if so where from and just how important are inner wings for structure?

And are there any other areas prone to rust other than the usual wing as running boards? most of the car looks nice but I don't know if any serious corrosion could be lurking.

Hope to hear back.