Not every radio is scrutinized by the fcc. The manufacturer sends one single radio off to a third party lab for testing.And that's stock, I thought that was odd too. Ssb numbers were pretty high as well which didn't seem accurate for an fcc cb radio. He also said that was at about 90% modulation which makes it even more odd.
They then send the results back to the fcc and if that radio conforms to the rules they all get approval.
There is one such lab less than 30 mins from me, I have seen them testing equipment for unauthorized emissions and they work with the manufacture to ensure that the equipment will get pass the specs.
The FCC no longer tests any radio in house anymore.