74 Dodge Dart Swinger. What’s it worth?

$500 and not a penny more.

That's not a "small bit of damage" to the passenger quarter. That's a full on quarter panel replacement. Also, look at the hole in the top of that same quarter next to the vinyl top trim. It's toast, rusted out from the vinyl top. So is the dutchman panel, and so is the trunk floor. I'd be worried about the roof skin too, and those aren't reproduced so if it's rusty you'd need a donor car to fix it.

It does have the desirable spool-mount V8 K frame and big bolt pattern brakes, but the value of those is about what the car is worth IMO.