Alternator ID & Help

Looking at replacing my alternator on my 73 Dart with a new chrome one but before I order a new one I'm confused with what I have ( no good with electrics ).
Here are a few photos




The one I would like & I think is the correct one is at Summit part number 7509DDP, Chrysler square Back, One wire Capable with internal regulator.
IS THIS THE CORRECT ONE & WHAT IS ON MY DART?
Thanks