I've been collecting MTH NASA items and I have quite a number. I have several switchers but I haven't been able to locate any of the 3 road numbers (10,11,12) for the O Scale Premier 3GS21B Genset Diesel Engine With Proto-Sound 3.0 (Hi-Rail Wheels).
If you happen to have one for sale or know of a shop or someone who has one I would really appreciate it.