More pictures of under side, spare tire well, maybe remove carpet show floor, rear window channel ect would go a long way to determine value.
If you have time to fix brakes new fuel tank ect get it so it can drive it would appeal to a much broader range of buyers. Maybe paint fender and door red. But down side you'd likely become attached to it and keep it if you got it driving.
Complete 340 Darts unmodified like that aren't exactly growing on trees these days. Not many 340 cars were factory AC either and looks like all the AC stuff is all there too. Red helps a lot too.