Is this transmission rebuilt or was I hornswoggled?

I bought a c4 automatic to swap into our bronco and I don’t have much experience pulling autos apart or really much more than just changing fluid and a filter on a newer one. I’ve only owned manuals!

This was reportedly rebuilt and has zero miles on it. What should/could I check and look for on it and on the torque convertor before I install it? For both problems and for evidence that it was rebuilt (and for indicators of the quality of the rebuild). 

the guy who I bought it from runs a small, unmarked shop and seems to have a steady stream of cool older fords.  He said he was a ford tech and rebuilt it himself.  

a local shop quoted me $380 to tear it down and inspect it but they didn't seem to really want to do it. And for that price I'd rather just take the guy's word for it and roll the dice.  Pulling it would be a pain but worth it to me to save $300. At least until it actually comes to that at which point $300 would have been worth it!

Wwgrmd? Run it, inspect it myself or pay the man?
 

Run it.  Only way to know if it was rebuilt is a pretty full teardown.  Not worth it.  If it shifts, run it until it dies.

I'd risk it.  Even if they just painted the torque converter to fool you, that means a removal anyway.  Once it's out, a C4 takes an hour to rebuild and $150 in parts.  It would take a genuine arsehole to go to all that trouble to paint a torque converter.

It's obviously not my money you're playing with but it sounds like a very moderate risk.

It's a C4 what could possibly go wrong?

If it's really clean and you can see fresh gaskets at any of the seams it probably is rebuilt. A c4 is one of the easiest transmissions in existence to rebuild so if you have an old ford guy bothering to do a real cleaning there's a good chance it's because he was rebuilding it. 

Install and go for it.

Send it. 

Yes!  Just the answers I was looking for. 
 

if it breaks and I decide to rebuild it myself, I will solicit everyone's help as I have never pulled one apart but try not to miss opportunities to screw something new up. 

WTF.  Try it.

And my wife just watched you in Baby Driver.  Again.

I always thought she had questionable taste but perhaps I was mistaken....  haha!

The guy sold it with no warrantee?

If you have a Bronco, you have a friend with a tow strap and a truck.  Just put that friend on speed dial.

I forgot to update this:

trans seems to be working ok. It was leaking from the kickdown seal so I put a different oring in and a washer to help and that seems to have stopped it.  I ordered the correct seal and will replace it soon just to have the correct part in there 

the pan gasket was leaking so I tightened the bolts and that seems to have stopped it. 
 

it does have a slow mystery leak, which drives me nutty but for now I'll live with it. Because....

I fear I might have an issue with it but wanted to try and describe it here for some feedback. 
 

I don't have much experience with older automatics but the little I have makes me think something is amiss.  Also, no tach so I'm guessing on rpms
 

it doesn't seem to have definitive up shifts most of the time.  Sometimes yes, but they are getting less frequent. 
 

I'll be driving light throttle and it will feel like it's getting past the point where it should shift.  Maybe 2500-3000.   I lift and sometimes it shifts sometimes not.  Sometimes it's a super long shift that you almost can't discern. 
 

if I'm holding in first (probably second as well but can't say for sure) and it's not shifting, I can usually lift and the engine will drop to idle.  Give it gas and it revs back up and the trans engages at the same point it just dropped from. 
 

I thought it was low fluid but I checked (car hot, idling in park on flat ground) and it seemed ok. Hard to tell because there wasn't a super definitive line. But it was registering for sure. 
 

I figured what the heck and dropped another 3/4 quart in.  
the next drive (my wife took it out) it was leaking quite a bit more from the top of the tranny probably in the rear.  I assume it was the vent. 
 

finally, the kickdown is not connected because I don't have the proper bracket on the carb. (We are putting a used fitech on soon so I'll hook it up then). I've heard of guys never running them and having no issues but maybe they are the same guys who have 250k miles on $10 shocks with "no issues" either. 
 

I know this isn't ideal, but does this seem to describe an obvious issue or could all of this be normal?

it engages drive and reverse nice and solid. I just don't know enough about these old autos to know!