Hey all, Went to put some petrol in the car tonight and got a bit of bad news in the process!

I knew it had some surface rust but didn't know it was this bad until this happened. First pic shows what it looks like when I put the missing bit back, Pic 2 is what's left and pic 3 is it attached to the filler cap.

Question I have is will this be a nightmare to repair? where would I be best go et a panel to replace this or is it going to be a lot of work? Should I cut my losses or do you reckon it's repairable? The rear arch on the same side has also bubbled so guessing the whole panel needs changed, does the filler neck attach to the outer panel? Does the metal locking bracket bit comes as a seperate part from the rear quarter? Been looking at panels but I cant see anything for an Orion just mk4 escort which is no good as its shorter than the orion