Rust......

Can I just add another thought? Your car is an f, which will make it the best part of twenty five years old (+). The plaiting on the main bearers is still in remarkably condition, as it was on mine. I don’t think later cars can boast that.
M

Thanks for the Sikalfex recommendation M, yes I was very pleased at the condition of the chassis rails.

I'll get some on order,

Re your comment on the scrap yards, amazing what used to be carried out secretly in the bottom of the tool box 40 years ago,

My good lady "adjusted" the rear door on her Kia Sorento recently and i found one in a scrap yard. I almost had a cavity search on entry and exit of the yard. how times change.

Just in the middle of replacing both rear wings, if you ever wondered what it looks like inside the rear wing, attached.

I've done a first fit with the new wing and all seems good. 

Thanks for that, interesting to see where the structural elements are!