I'd wager that no less than 60% of my Mach 1 is repop sheet metal. The fenders, front & rear valances, quarter panels, outer wheelhouses, taillight panel, trunk lid, floor pans, seat platforms, trunk pan & drop-offs, and rear cross-member. It might've actually been easier to mention what's still original (hood, roof, doors, and upper quarters). :whistling:
I don't see the issue with using repop parts because my car is not rare, collectible, or inherently valuable. It's just a fun car that I built for my own pleasure, rather than as an investment or as part of a valued collection. The repop parts are 'close enough' for my purposes, since an H-Code will most likely never tip the auction for more than $30K in the absolute very best condition possible... let alone one that's been pieced back together and resurrected from the dead. Sure, I've got WAY more than that into mine, but I'm also a realist knowing that I'll never get it back were I to sell it - I would value my car in the mid $20s, if push came to shove (which is about half of what I told the insurance company, of course
).
I'm not sure if the quality has gotten better or worse since I did mine, but I can honestly say that I had very little hassle getting the repop sheet metal to fit my car. I had to split the rear seam of the quarter to get the wrap-around bottom curve just right, then re-weld it. The hood being original presents its own unique issues when mating up to repop fenders, but I do envision the need to replace it at some point down the road (since there's no way to really get all of the potential rusty bits totally eliminated within the interior structure of the hood 'sandwich'). When I do, it'll be a repop hood, and I'll make it work.
Regardless of the source of the replacement piece, chances are very good that there will be some work involved making it fit. Most likely, the car will have been hit, requiring the damaged piece(s) to be replaced... which means nothing is going to 'fit right' without some work. Some pieces will fit better than others, and some will be better quality than others. That's just the way it is these days, since the market for factory replacement parts has all but dried up, which after almost 50 years it's to be expected.
Obviously, if the car is rare, valuable, and/or collectible, take the time to find and spend the money for the NOS parts for a faithful restoration. But if you're looking for a quick and less expensive way to get things back together, there's nothing wrong with the repop pieces, in my book.