How much you do really depends on you and what you want to do -- how much you want to put in it. There's nothing wrong with a little bondo. Many new cars have it right off the showroom. You think they pull a quarter panel that gets a few dings before leaving the factory or coming off the truck at the dealer? No, they repair it.
That car had a lot though, in some critical areas. The rear quarters DID have a drain hole from the factory. The people who "repaired" that one didn't put one in, probably covered the factory hole. The factory usually just leaves a small gap where the lower panels come together, there's a raised section from 1/2" to 1" long that has maybe a 1/16" gap, the rest mates together.
Like anything, there is a proper way to use body filler and there is a hack job. At least the guy who filled those places at the top of the quarter used a metal underlayment instead of stuffing with newspaper and slathering bondo over it. The metal underneath meant the bondo wasn't real thick. Since the hole was so big I'd call that a hack and not a proper repair. That small corner on the other side could be repaired with bondo, or better a product called "kitty hair", which is a fiberglass jell with fine chopped up strand of fiberglass in it. Some thing large needs metal welded back in though.
Another tip on the body panels -- if you have a friend that works at a body shop see what they can get the panels for. Sometimes they can get them, even antique panels, way cheaper than the restoration houses sell for. Even if they can't save you on the panel, they can usually save you a lot on shipping.
Check under the rockers and the vertical inside panel of the rockers. The rockers are the main support for the body. Often northern cars (and west/mid west -- winter salt country!!) with that much rust have the inner rockers rusted out. There are patch covers for the outer rockers that may have been used on yours. Looks like salt ate the top of the right rear rocker out. The tire slings it up. I thought those bodies had plastic wheel well liners, but that one may have been removed or got damaged.
You'll have to talk to the guys who make the patch panels/quarters and see just how much needs to be cut and where. It would be nice to get a factory service manual (body manual -- I think GM usually had a Body and Mechanical manual). That will show you exactly where to cut the panel and/or drill the spot welds out. The panel maker may have an illustration for that too -- check!
Definitely replace badly damaged panels that bolt off, like the front fenders. Small holes I'd weld patches in, but if more than a little rust underneath replace it! Even if you don't replace the front fenders PULL THEM OFF!! They may be hiding extensive rust. Before you put much money in that car check it ALL OVER for rust. Take "inventory" of how much needs to be repaired, and tally up parts costs. You might find that you can get another body cheaper, even if having it shipped from the south or dry states out west.
Technically it's illegal to "rebody" a car (use a rusted car for the serial number and some mechanicals, transfer to a rust-free/more repairable body). Practically it's done all the time. Federal law says a VIN can't be altered, once it's on a car it stays. The thing is it's not enforced unless someone complains. If you know you have clear title to the rusty car and you're sure the "donor" isn't stolen or otherwise illegally obtained, it can be done. The only time this might be a real problem (other than the obvious -- the donor is stolen) is if the car in question was a really rare car or rarely optioned. I mean like a rusted/trashed late 60s Mustang Shelby GT350 VIN/parts transferred to a run of the mill Mustang fastback. That's done more often than you think, but it's a real gray area. If you totaled a 66 GT350 early in the model year you could order a factory "body in white" (non-serialed body shell, usually in white paint for protection, hence "body in white") and legally transfer all the parts. Or a 67 shell (I think the 66 and 67 shells are practially the same...). Do you still have an "original" Gt350? It's a rebodied car, not the original body shell... so I call it a gray area. When you change the VIN over the car practically becomes the car the VIN was made for, assuming all the original parts (or suitable replacement parts) are used. But now we're back to technically it's illegal to "rebody" a car.... Your car, your decision. I'm doing this now -- but it's on an old Jeep J-10 truck. I have a good cab and frame from one with no title (I knew the original owner, I could probably do a lot of paperwork ad get a legal title, but...). I have a rusty one that I have a title to and will use a few parts from, but even the frame is so rusty it has flakes coming off, even the engine block does! I certainly don't trust it enough to put money in! So the VIN plate is coming off and going on the good cab.
Technically illegal, but nobody cares, and it's not a real collectible vehicle. No harm done.
Last edited by farna; 08-15-2012 at 07:26 PM.