Yes, but proto information is the info that matters here. The next question is which proto is the model.
My understanding (proto) is:
- Bi-level Enclosed - 33"
- Tri-level Enclosed - some 28" some 33" - how do we sort this out?
- I assume open bi-level racks are 33"
- What about open tri-level racks? - 33"?
As for models, if we ignore the Concor model, then we only have two enclosed prototypes to deal with (RC and MT).
For the RC bi-enclosed rack, it's safe to say it's proto rides 33" wheels (right?)
For the MT tri-enclosed rack, what did its proto ride on?
OK, here's the thing. You can't really go by the rack to determine wheel size, at least not for 60's-70's era stuff. In the modern day it may be simpler. The wheel size is determined by the flat. So to answer the question about open rack car, you have to look at the flat, it's the only way unless maybe you can become an expert on the various racks and know that there were some in particular that would only have been put on a low-deck car. There were also low-deck trailer flats that used 28" wheels.
But all that's really important is what to put on the currently available models.
About the only MTL model in this fight that has had prototype pinned down is the 89' flatcar. It's a late-60's/early 70's ACF or PS flush high deck (or high level) car which would have 33" wheels without question. AFAIK, the open rack cars are the same flat with a rack put on so the wheels are still 33". These cars are plausible and I think you could come up with a picture of a tri-level rack on that type of flat from that era. The problem is the closed rack car. Is there even a prototype?
Here's what I've surmised from all that I've read, proto and MTL descriptions.
In the 70's, most of the tri-level cars got shopped to get a fully enclosed racks. At the same time, many (most, all?) of the high deck car were removed (if not previously) from tri-level service and put into general trailer service or maybe bi-level service in favor of low-deck cars. I think the MTL car is supposed to represent these cars that got shopped with new racks, but in typical MTL fashion, no regard was given to reality. I think the flat used under the tri-level is basically the same flat as they used previously in which case, the car would still have 33" wheels even if all the proto paint schemes they use had 28" wheels. Regardless of what I think, there is nothing about the MTL enclosed flat to even suggest it's a low level car.
Some may decide to go by the proto scheme to determine wheel size, which is fine but will make the car look even more ridiculous. But if you do, your following the lead of a company who painted these tri-level cars into this scheme:
Those have the reporting marks 'TTGX' which I believe by definition, are bi-level cars. So follow away...