I am aware they are fiberglass. That is wthy I made the note about the spacers along the inner fender and the valance. On the left side I had to fabricate some spacers that fit the length of the valance- it was made out of metal, to get it to the correct thickness I had to choose between running a mill or making some passes with a surface grinder. My surface grinder is old- Rockwell "Toolmaker"- so what I had to do was mill it within a few thou and then used a belt sander with an extremely fine belt. At the area of valance attachment I was reticent to remove material from the fiberglass. I have a Lotus, I have two Fiberfab cars- when I perform repairs- it is a case of walking a tightrope over a sewage treatment field- one slip and you end up in deep crap. Because fiberglass repairs are never pleasant.
When you work with fiberglass there is an absolute minimum to flexibility and there is an issue where if you are using metal pieces you have to work the metal rather than having to adapt the glass, and it is counter intuitive.
U.S. Body has one of the few molds for a heavy, bolt on fiberglass 70 Charger hood. I have fitted one of those. They are not available because last I heard he had to get a minimum order and then would need to pull from the molds. If he does and one shows up for sale I'll buy it and use it.
He had a complete shaker set in fiberglass minus the doors which were easily gotten.
The Taiwanese availability of sheetmetal is dwindling. I've called around to a couple of other vendors and they don't want to talk about supply issues, but I have heard three times "It's not that we don't want to carry the line- that's all that we can say"
I have a friend in Cumming GA with a yellow Dart he sold as part of his divorce. A father bought it for his son, the son treated it like $2000 beater and it ended up on the highway between Cumming and where I-575 starts. Pete stopped and it was his old car except it needed a full quarter, inner trunk extension, a trunk pan, rear bumper, a rear longitude looked like it needed replacement, and it needed a rocker panel. The son had moved on to a lifted cateye Chevrolet diesel. Pete restored the car originally and he spoke to the father who wanted to recoup nearly the original purchase price, the mother heard Pete leave a message asking about it and she essentially said: "Sell the car Earl, I don't like having that ugly thing in the drive." Pete got it back. He asked about sheetmetal- one vendor that is Taiwanese and I'd bought through Jegs was completely de-listed. Another had no stock. Year One had some AMD pieces. I told him if he was in a hurry- go to Flowery Branch and get what he needed.
It was put on a frame machine when the quarter was cut off and we did not have to do a longitude. However the quarter panel was straight out of the JC Whitney days. Much like art- whether that quarter was for a Dart or a Chevy II was in the eye of the beholder. It was AMD. Looked online and for Darts and AMD that is apparently not uncommon. The trunk should not have needed replaced but to get a suitable panel had to buy the whole thing to make it work.
I bought pieces from AMD for an E-body 'Cuda and there was an agreed pickup date, I even called the day before. The AMD parts were not "ready to be pulled from the warehouse" and then their "certified forklift driver" was not there but I watched a box truck that had come in when I did leave with the rear sagging where as it was not before hand. I finally got the parts on the trip. The taillight panel needed a manual flanger to finish out the panel whereas it was stamped correctly in other places.
Last time I bought some pieces for a B-body I just went ahead and called the place that was listed on Jegs and I asked about their "OEM quarters" which is a bigger panel- the lady in purchasing/inventory said "You might want to buy those if you want them." That is the economic principal of signaling, something so subtle it got Vernon Smith and Daniel Kahneman a Bank of Sweden Nobel Memorial Prize- I'm serious about the prize but mocking them for getting it. She was telling me "When the wind done gone, breeze a long time coming." For you non-hillbillies that means "Read the room" aka "Read between the lines"- she was correct- their quarters were gone and I got one of the last sets and drove to Asheville and got them at the terminal.
Same place had a bunch of A-body Olds, Buick, and particularly Pontiac parts. A guy I did a lot of work put me in his will to receive a 1970 GTO project "he was going to get to". I second hand sourced enough pieces to do it.
I'm not saying that AMD is the great Satan. I am saying there are 3x as many Ford and GM cars produced versus our Mopars. AMD chose to go where the money was and over time their quality slipped and slipped- across the board.
Now ? Pay for OEM used excellent and get a third job to do it. Or work with what is out there.
When we put the glass fenders on the Coronet the owner said "I'm kinda worried about a collision" I pointed out that if you get in one and you want to save a 50/60 year old unibody car then you best be ready to do what Pete did with his Dart. Glass may shatter or break, sheetmetal tears and distorts too.
Thank you, come again. The opinions expressed here are worth as much as anyone else's but probably less. Best.