The parts book for '52 & '53 shows 2 Idler Arm support numbers, #806797 UP TO ser no. (blank) and #809761 AFTER ser. no. (blank). There's actually 5 bushing part numbers, .010, .015 and .020, once again BEFORE an unspecified serial number, and 2 more, .005 and .010, also listed as AFTER an unspecified number. I'm guessing these reflect minor production run or supplier changes, very common.
Support #809761 is also the support listed in the '54/'55 book as well as the .005 & .010 bushings with the same '52/"53 part numbers.
Last fall I fully tore down 3 steering assemblies ranging from a very early production '52 to a very late '53 (early '54). I saw no noticable difference between idler support brackets. I did luck onto a new bushing at the time and somehow twigged out the groove system then, and also notice one bushing had a slightly taller hex with a spring inside but the same internal threads. Sorting for the nicest parts & tightest fit, I swapped parts around, everything interchanged.
I have a "Popular Parts List" book for a wide variety of Jeeps, Wagons & FC up to the '60's and don't see any part similiar to this bracket/bushing. Since the bracket and bushing in the auction above looks exactly like the three I had last fall I strongly suspect that the sellers "9" in the part number has been incorrectly transposed to a "7" sometime in the past 60yrs................... just my opinion.
Everything this seller has is listed as Jeep, but if you look carefully, many Aero specific parts are salted throughout his litings as being Jeep parts.
Hope this helps!