Wow - that's pretty... ummm... different, that's for sure. :chin:
Putting it back to original wouldn't take much at all. I'd be willing to wager that center console 'thingie' could all come out of there easy enough, and maybe even sold to someone looking to go that direction in their customization - it looks like a quality-done fiberglass console (probably made by whomever installed the stereo system). After that, it's a matter of new dash trim, center gauge cluster/trim, center console, seat covers, steering wheel, shifter knob, door panels, and maybe new carpet. The whole interior could be restored with new repop parts for under $2K (ask me how I know :whistling: ). Outside - a new set of rims/tires, repaint the hood and you're there.
Otherwise, looks like a decent enough car. I actually kinda like the way they did the stripes on the hood, and the late-model Mustang rims don't look half-bad. I'm sure there's more to it than that (there always is), but it looks like a good deal to me. Everything looks like cosmetic changes that are easy enough to put back to original (if that's the plan).
Knowing what I know now, I'd get that car and make it mine for the best price I could get up to $9-10K (providing it runs and drives, of course). Once back (or closer, at least) to original, that car could be flipped for $15000+ (again, depending on how everything else is - those pics aren't really enough to make the most informed decision, of course).
'73s aren't my favorites, but I like it. ::thumb::
Good luck!