Ken: Thanks for prompting me to go back to Parts Lookup with renewed vigor. I checked the three (3) hitches you mentioned, and it appears that they are associated with the deck, not the particular tractor under which they're listed (this fact was one of the original sources of my confusion).
So, the missing piece of information you need to correctly interpret the listings in Parts Lookup is the Serial Number they reference. I'm posting a chart I probably downloaded from this site, but it is the most concise listing of serial numbers that I've found, and it allow me to make the following statements:
(1) The first hitch listed for the 38"/42"/48" mowing deck was designed for the earlier narrow frames that do not have the Quick Attach feature. Parts Lookup references SN 65,458 to 218,009 compare the SN listing in the chart below.
(2) The second hitch listed for the 38"/42"/48" mowing deck was designed for narrow frame tractors with the Quick Attach feature (which is integrated to the frame, it is not "bolt on"). Parts Lookup references SN 218,010 to 400,000 compare the SN listing in the chart below.
(3) The third hitch is the one I want, it was designed for the 1x8/1x9 series --the early Wide Frames with the Quick Attach feature. Parts Lookup references SN 400,001 to 529,999 compare the SN listing in the chart below.
(4) The hitches I pictured below spread out in my back yard were a selection of Quiet Line and 82 Series hitches from SN 530,000 to 665,000 and 665,001 to 700,000 respectively; as the ever insightful Matt Gonitzke pointed out.
Again, thank you Ken, for helping me deepen my knowledge of Cub Cadets; I think Myron Bounds would be proud of both of us.