Grzyboski's would have purchased that engine from someone else, so who knows what its history is? Engines can be briefly test-run on straight track and still appear to be unrun. Also, testing is often done using electrical clip-ons, and the engine isn't placed on track at all. So it is virtually impossible to say what the history is.
Regardless, I certainly would have contacted Grzyboski's about it at the time. They might have been able to provide some information about the engine, as well.
I have those same engines. I swapped the shells with some PWC F-3 chassis, because I run a command layout, so they now have TMCC, R/S, electrocouplers, directional lighting, cab interiors with crew, etc. I thought about the Legacy version when it came out, but didn't care for the black roof.
