He reverse engineered it from build sheets, fender tags, former employees, documents etc.
It was probably a ton of work, and something he definitely deserved to be compensated for. Unfortunately once the knowledge of decoding became available to the public, that particular service became a lot less valuable.
Now he is more of a "seal of approval". His documentation is supposed to certify that the fender tag/broadcast sheet/window sticker/etc is legit. In the high end collector car world, his name does still seem to carry some weight.
ok, sounds fair to me he charges for his services, it obviously took a lot of time and efford to gather all info. I think things went wrong when ego grew above his head. No matter what business you`re in, if you don`t keep clients happy ,you go down.