Is the Serial lower than 17271035…?
From the TCDS:
DATA PERTINENT TO ALL MODELS 172 THROUGH 172Q
…
“Equipment:
The basic required equipment as prescribed in the applicable airworthiness requirements (see Certification Basis) must be installed in the aircraft for certification. This equipment must include a current Airplane Flight Manual (AFM) effective S/N 17271035 and on.”
(I could be wrong but..Up until the Q-model I believe they were Placarded airplanes. I had to buy the official placard from Cessna for my C-model.)
From TCDS:
“Models 172, 172A and 172B
"This airplane must be operated in compliance with the operating limitations stated in the form of placards, markings, and manuals.”