patrolpilot and wslade2, thank you both for your input.
I think I mislabeled the "front/rear" on the image I attached at the beginning of this thread.
In my "P" manual both placards are shown as item number 38. Item number 38 in the textual parts listing is just one item and shows- 1 "Units per Assy", and no- "Usable on Code", so the placards would apply to all planes covered by my parts manual.
I'm thinking there is one placard for the front cowl flaps (as it has the vertical rod), and one for the rear cowl flaps (as it has the horizontal rod) and both placards come as one "unit" under part number 1500022-2 since they are each shown to be item number 38 ... even though there are two actual part numbers as shown on the placard images in the parts manual. Cessna hasn't made this easy to interpret.
I expect these placards are long gone from most of our planes. I know I certainly don't have them.
If no one can definitively tell me where these placards attach, then perhaps after I get the cowls back on, I'll look for the best place to afix them.
Rick