Re manuals, sure, the FAA too in theory requires the latest manuals, but the "fact" is that most firms do not subscribe to the latest $1000/year ATP CD manuals for every type they work on. Many work off many years old microfilms. The GA maintenance scene would grind to a halt if this was actually enforced. It would also make a mockery of all owner maintenance provisions.
To clear the air, it is not an oversight of enforcement that allows firms, or individuals to perform maintenance without using the most current mfg's manual.
It is clearly stated in 14 CFR part 43.13.
§ 43.13 Performance rules (general).
(a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer,
or other methods, techniques, and practices acceptable to the Administrator,
In fact, most maintenance manuals for light GA aircraft are not even FAA approved.
It is perfectly legal to use an outdated manual as part of "other methods, techniques, and practices acceptable to the administrator"