I would totally let someone pull apart the dash on my Mustang, right after they paid me for it and drove it home...

Helpful checklist for future mustang purchasers! Hoping that the rust can be maintained and controlled!

The fixture at the 7:33 is an old school air valve. It  allows the engine to breath. PCV (Pollution Control Valve). It supposed to recirculate unburned combustion gasses.

Most important thing to check are shock tower cracks along the upper control arms. Almost every Mustang from 65-69 with the exception of factory big block 67-69 will have some degree of cracking. Big block cars have additional plates wrapped around the lower half of the shock towers. 70 was the first year that implemented this extra reinforcement regardless of engine size. Cheers 👍🏻

hi beams are the button on the ground. that extra pedal is the wind/wiper fluid pumper.

A lot of what you described are common and even expected from an old car, classic or otherwise, that hasn't been well cared for.  It's has been tinkered with a lot by the previous owners.  When aftermarket intake manifold and carburetor was installed, lot of the emission features were removed.  This is usually the case with performance-minded people.  The vacuum hoses (7:06) are that way because of laziness.  The vacuum ports are not even used.  You can simply remove the vacuum tree and plug up the hole.  This thing (3:29) looks like the turn signal blinker unit.  But then again, there is another one hanging down below near where your right shin would be (2:56).  What gives?  That stuff (5:39), I believe, is the sound deadener from factory.  The stereo speakers are not necessarily installed from the factory on all cars.  They were optional.  For the age of you Mustang, this is exactly what I would expect from minimally maintained car.  I have a 1969 Mustang.  I bought it when the car was only 14 years old and it was already looking like your, except that mine was still relatively "not old."  Everything you showed are very minor fixes, except for electrical.  The corroded battery terminal: take baking soda mixed in water and pour it over the corrosion.  Then rinse thoroughly.  No need to replace battery, unless it's testing bad.  BTW, in your previous video you showed "AC" pump.  That is actually the smog pump that's been disabled.  Being a three speed, it's likely not a GT.  If it was a GT, I would restore it as a GT and not modernize it.  I'm actually exited to see how far you'll take this project.  Waiting patiently for updates...

Dead on right Jeff, I made the mistake of not checking some of these before. didn't end well lol. great video, I subscribed and look forward to more videos.

Hey Jeff What’s your wheel set up

Isn’t that a vacuum hose ?

You can def tell you aren’t a mechanic  bc every single thing you pointed out is an easy fix.  These can all be fixed very easily.  The main things you should check on a mustang before you buy are key well known spots that are known to rot away like strut towers.

Not sure why anyone buys this old junk. 🙃

If your not mechanically inclined I would stay away from working on classic cars, the problems you have with your mustang are nothing compared to floor rot torque box rot fender rot.