The U.S.A.F’s ‘Attack Experimental’ (‘AX’) program

The U.S.A.F’s ‘Attack Experimental’ ‘AX’ program

Does anyone have any information as to the other designs that were submitted to the USAF, to meet their 1970 Rfp (Request for proposal) for an ‘Attack Experimental’ (‘AX’) program.
The only designs I know of is the winning Fairchild A-10 Thunderbolt II, and a little about the Northrop A-9 design submission (Info on the A-9 also welcome). While the other submissions that I have no information, drawings or specifications are from Boeing, Cessna, General Dynamics and Lockheed.
(Note- I know that Lockheed’s design was designated the L-1400, and was a kind of low-altitude and armoured U-2 of sorts)

Can anyone help with this?

Regards
Pioneer