Chuck Greene wrote, " I'd like to see a prototype that might have been saved."

There used to be a Union Oil tank  car of this sort at Travel Town in Griffith Park, LA.  Actually, it could conceivably be the prototype for the model since Roundhouse was based in LA back in the days the kit was first issued.  I don't know if the Union Oil car is exactly the same, but it is close.  Unfortunately, I haven't been there in decades.

Chuck Soule