Saginaws were used by 1969 on some models, so there's a good chance the pumps on your 1972 & '73 can interchange.
Look at the tank. If the cross section of the upper half is oval shaped instead of round, it's a Saginaw. You'll need to swap brackets. If the nipple for the fluid return points in a direction that's very different, you may need to swap the tank to the good pump. That would give you a good reason to reseal it with new gaskets and o-rings. The reseal kits are cheap,