Tank cars 1948 GA design in Black. Were are they?

Why am I not seeing O scale General American 1948 design 8,000 gallon welded general service Black Tank cars? I see the Hookers, etc. but never the all black tank cars? This is all I ever seen around my region being hauled by the railroads, 5 of them. Never seen any privately owned cars. Have any ever been made by Atlas, Lionel, MTH, etc.?

I would purchase 8 to 12 of these if produced.

One other thing I see little of on many layouts is stock cars. Yet I remember long trains of these even into the late 50s and early 60s on their way to Chicago.