Ed Sutorik wrote:
"I got it into my head the the B&LE car was the prototype for the Ulrich triple. Comparing photos, I see that it is not.
Does anyone happen to know what the prototype was for this model?"
Look again - B&LE had more than one type of triple hopper.
See also Richard Hendrickson's article in the March 1984 issue of Prototype Modeler.