Whats my 72 dart swinger worth?

If you really were offered $5k, you made a mistake by not taking it. $5k can buy you a decent daily driver one. Your's currently is not a driver. Also, custom things that people do to their car that are their taste, don't always impress others.

All the stuff done in the engine compartment looks okay, but I would rather have a more stock looking engine compartment. The Swinger emblems in the leather durango seats, I wouldn't want that. Basically what I am saying is you can't add things like that to a car and expect more. I have worked in the auto industry for a long time, and you learn really quick that things like stereos, wheels, lowering kits, etc... don't add value to the car, because it lowers the projected demographic of who wants it.

Not bashing on you or the car, just making a point. The car looks fair, but miss matched wheels, cut out wheel tubs, stuff like that hurt it. I am thinking $2500 at best currently.
Maybe more when the wheel tubs are installed, if they are done properly.