Mopar Bumper Jack ID Help!

I assume my 72 duster has the original bumper, it has a slot in it that takes a jack with a little nook that goes into that slot. the body of the jack is hollow, the earlier jacks ( i'm thinking 71 and olde), were solid and 3 sided. different bases for each style post. THE JACK i'm talking about is plentiful and not expensive.