One is free to speculate, but the down-to-earth information available up until now says that this was a car like thousands others:
- 360 ci engine, nothing particular for late 1974 Brougham production. (That's what I meant with "K-car");
- no known special codes on the fender tag or the broadcast sheet;
- specifically, there is no information connecting this car to police, government or commercial fleet use;
- possibly a special code starting with "9" in the VON in connection with late-model-year production, but nobody knows what it could mean;
- like
@69CoronetRT said, wheels are easily changed later on and don't say anything about the set-up as delivered;
- that a locally well-known farmer specially ordered this car does not show (Y14 "Sold Car" could have supported this claim, but it's not there).
Enjoy the power pick-up and leave it at that! It's still a nice-looking 1974 Monaco Brougham!