Concerned

hi duno were to post this so i'll dump it hear that way cant be moned at . well i started striping out Frankenstein today redy for his whole new interia it had rockwoll behind panels when i got it and was worried it might rust, well it has! its got a small hole and loads of surface rust witch is starting to disovle in my blood after getting a wire brushing. neway its in the bit next to the engine bay on top of wheele arch behind the triangle bits between the skins if you get my drif and was wodering how to repair it wther i should wire bursh it Krust it and then put some fiberglass filler then hamerite it and primer it witch is what i did on tail gate corner which is still good or try and get it welded but it look awkward to get at without taking outer skin off! and that sound expensive the hole is bout 5x15 mm on the base of vertical bit in the last triange. i know i ramble a bit but its hard to explain. and advice welcome.

Fibreglass/filler is seldom, if ever the proper answer to stuff like this, especially on areas of the body...

take a pic and post it. cos I dont have a clue which bit you mean