This model is based on the N&W H11a-H11e series of coal hoppers (although MTL uses them as stand-ins for other prototypes as well). As pictured above, these cars are available with coal loads.
In 2018, MTL released a closed-top version of this model -
The model is based on prototypes that were temporarily converted into covered hoppers with the addition of a bright yellow fiberglass “Hopper Topper”. Said cars essentially became grain hoppers, and were implemented by Chessie System, Conrail and other roads in the 1970s to help meet demand during seasonal increases in agricultural production and other commodities.