My experience in the UK, is that many repro parts suck big time! So much so that a supplier accepted back an inner wing/fender that Id welded in place only to find that several critical holes were in completely the wrong place. There was no way it could have been adapted.
It is a much smaller market here and we often have to make do with what we can get. Its not right but there are often no other options.
Anyway, back to my fenders.
This is what I found on Tuesday night when I started to work on the front of the wing
Even that photo doesn't show the tear fully
Ive not removed the filler on the outside of the rear of the wing but as you can see from the inside its pretty rotten
I can repair this but the question still stands, its going to cost about $150 for parts to repair an old wing (and I don't know for sure its an original, it could already be a repro part, though Im reasonably sure its an original part) against $200 for a complete wing.
But bearing in mind it will have to travel to Scotland there is a high probability a complete wing will get some damage where as the patch parts are less likely to be damaged being smaller.
One thing that worries me about the parch panels is the fact they may be made from a different thickness of steel. That can cause difficulty when welding them together but also possible visual differences where the edges of the panels join.
I guess at the end of the day I pays my money and takes my choices! I guess if I save $50 then that $50 I have to spend on something else that I need. The repair time is sort of insignificant in the grand scheme when I consider the other works I have to do.