Night Sailor, best I can explain it is a capacity plate ain't no different than Confederate money. Not worth the crap it was printed on.
However, some jurisdictions have made it their rule to require them basically to make it easier for the policing authority to write tickets.
I've had two boats that had bogus capacity plates made for them for the purpose of overhorseing the boat to try and fool the game warden or coast guard.
The "History" section is probably the closest thing you are going to get. But it does not have weight/passenger capacities.
http://www.wellcraftv20.com/gallery/history