What kind of brakes do we have? Confused...

Looks like we've lucked out in all sorts of ways on this. Thanks for all the support.

Wife went to bed early tonight so I went and slid back under the car and confirmed the transmission number is 4058383 6997 1390.
Once you get the brakes rebuilt, you'll have a nice foundation to start with. That slant 6 you have is a great engine, and once cleaned up & tuned will last a long time.