Is this the correct car you are looking for? 056 00 000 33' 2 Bay Rib Side Hopper, Flat Ends Jan 1977 This car is supposed to be a clone of the USRA twin hopper. Unfortunately, the stirrups are different, the slope sheet angles are different, and the MTL car is missing the characteristic sill gussets that the USRA car and clones were built with. The MTL car measures out to a 30' 32' inside length, compared to the USRA at 30'6" The MTL sides are 7' high, while the USRA design is 7'5" So even though the cars are similar in many overall areas, I think they are fundamentally different. Apparently MTL stretched a two bay to fit the offset twin frame (55 00 000). The Ribbed 2 Bay ‘prototype’ is actually a shrunken Athearn twin clone. To put it another way, if MTL's goal was to make a USRA clone, they did a lousy job. The MTL rib side is close to some real cars built in the 30s and 40s, VGN had a class of twin hoppers very close to the MTL car.
The MTL car is a 33' IL 6-Panel hopper that reasonably matches cars built for Virginian and Southern Railway in large numbers. Some of these cars later ended up in RI and N&W fleets. DL&W also had similar cars. GM&O rebuilt some cars into this arrangement although the ladders were different. Over the years, MTL did a number of paint schemes that were actually on 30'6" USRA hoppers, using their car as a quality stand-in. The USRA cars are now available from Bluford (shameless plug!) Craig Bluford Shops
