MP 31400-31499 also had Duryea underframe, as noted on Ed's list. I buy your logic in not covering these, since Atlas didn't attempt to model them.
I've picked up a few of these on eBay, and I'd use this list to pick up a few more but most of my rolling stock is packed and I don't have records of what I own.
Side note -- I built several of the Sunshine MP cars, and still have one or two unbuilt ones from other railroads. But I've picked up at least one each F&C and Yankee Clipper MP cars, so if I build those I'll have models of 1932 cars from four different builders/