That’s great!
@SGT FURY — The 1973 would all have openings to accommodate the legally-mandated big bumper guards. In 1972, the guards were optional and smaller (option M85 for front/rear bumperettes, M81 for front-only). Dunno if the holes are different between 1972 and 1973 bumpers.
--> is the part number stamped in the bumpers?
@Newport Woerden — you should check if the 1972 and 1973 parts manuals show different numbers for the rear bumpers. If memory serves, PDFs of both are freely available online at MyMopar — otherwise let me know and I can email them to you.
Since CL23M2C136951 does not have either option (M81 or M85) as per the build sheet and order sheet that you
posted, you can enjoy the true fuselage loop bumpers without appendage.
--> I would bet that the bumpers that SGT Fury has that don't have holes are the ones you need for your car, but do check the part numbers to be sure.