The Auburn clutch was used in many original IH tractors. There were just as many if not more Rockford style clutches used. I feel the clutch suppliers were actually used as dual source suppliers of clutch components. The Rockford was considered heavier duty, but no one I know of complained about the Auburn as being weak or quick to wear out. The reality is that there are few Auburn type clutches available. One would need to search for NOS, or a good used, or a rebuilt unit.
They are interchangeable, so purchasing a clutch kit will provide a Pressure Plate looking like the Rockford Style.
The Auburn pressure plate has a "bridge" with three arches going to a center hole, and usually three heavy springs. It is more open in design. (google is your friend)
The Rockford is more traditional looking and has a more full cover over the mechanism and may have six springs. Jim