Looks like yours might have been a little later with different insecticide shut off.

Mine is a very early 7200 as it still has 7000 cable style markers.

Your picture appears to be twin 13" spader's and looks like the 3 bolt aluminum hub needed to get the offset for the short 7200 closing wheel bolt.

I bought the 4 bolt cast hub which included the steel spacer plate. I've also got several opener disk shims on the closing wheel bolt before the hub went on to. Basically I'm out as far as I can go and still get a full nut on the threads. I've got 2 rows that are rubbing the others barely miss. I need to do something to get a little more clearance somehow.

Martin pamphlet says 1-7/8" at narrowest point between a spader and rubber tire. Somehow I've got recurring visions of the spader flipping all the corn out of the row