Totally understand on both accounts, I have two cars with all of their major numbers matching and quite frankly I should sell both of them because it's just not my jam. Much happier with my non-number matching cars that I can do whatever I want to without anyone thinking twice.
That being said, for $50k a '69 340 Dart is going to need to have some documentation and evidence that it is actually what the seller says it is. But that has its issues, because good old Ma Mopar was pretty far from perfect when it came to rules and exceptions. I mean, I definitely wouldn't call anyone a fraud because they're missing an exhaust hanger 56 years after the fact. There are so many perfectly legitimate reasons why that could have happened it just makes no sense at all to get worked up about it. Yeah, if you're the one buying it you should check the numbers.
But getting in a twist over an exhaust hanger on someone else's sale thread? C'mon. The car has been redone multiple times now. Any evidence of the presence or absence of an original exhaust hanger would be dubious at best. Doesn't mean the car isn't legit. Doesn't mean it is either. I'd be far more concerned about the VIN and body numbers matching. Beyond that, Ma Mopar wasn't nearly consistent enough to call someone a fraud over it. And more than that, I'd be far more concerned about the quality of the work done, because clearly a lot of work has been done. That's what's going to bite you in the ***, not whether or not a hanger went missing or was never there.