The central purpose of the Monroney was to eliminate "free-form" dealer pricing.
Applied at the factory, as it also confirmed which dealership the car was to be delivered to.
I remember them always being on the lot cars, but generally removed at time of delivery if the buyer requested it.
I removed mine myself, up through my last new car in 1989.

Side note: Over the years, I ordered many cars ( usually work cars), and there was nothing "special" about it.
You chose model, color, and equipment.
If a match or near-match was on the lot, or another dealer had one, those were quicker sales.
If not, you ordered & waited for it to show up.
That ordering term has been hyped & distorted over time.