Vacuum advance identify

My 74 Dart 318 donor car had a points type distributor in it .

I have no clue as to age of distributor.

It shows to be a refurbished one and there are no stamped identifying numbers that I can see. Looks like sandblasting cleaned them off, if there were any to begin with.

The vacuum advance leaks by, so I purchased an advance from NAPA, # VC3031, but there is a difference on the connecting arm-orientation to advance plate as shown by photos.

Can anybody possibly I.D. what I have so I can find a correct vacuum advance?

Thanks FABO!!