According to the Collectible Automobile information about these 1972-79 Ford Ranchero, there were three different trim levels out at the market. They are 500 sedan pickup, Squire sedan pickup and GT sedan pickup. I'll go through them and update accordingly.

Source: Publication International, Ltd., "1972-79 Ford Ranchero: A Finished Product", Collectible Automobile, Volume 37, Number 1, June 2020, Pg 22.