Mark - I recently purchased a couple of the MTH TOFC cars - hard to ignore at $35 each and free shipping on eBay! I haven't done a careful side by side comparison with the SHS (original?) version, but the flat cars look the same (decking color is different). While the trailers on the SHS car - at least the UP version that I have - are 6.5 in (35 ft), the trailers on the MTH cars are 8.5 in (45 ft). Perhaps SHS had the longer trailers too and I am just not aware of that or the longer trailers from MTH are new and don't use the SHS molds. The few MTH cars that I have (ore car in addition to the TOFC) seem to be well built and well detailed - not being a rivet counter maybe there's some prototypical details that I'm missing.
I keep hoping (against hope, likely) that MTH would rerun the SHS 2-8-0... (and that I could afford it).
- Rich