On Youtube, if you've not seen it, check this link.
http://www.youtube.com/watch?v=iInacGX7djI
This is somebody's home movie, in color, with the RR show starting around 1:32. It concludes with the NYC's "Commodore Vanderbilt" facing Pennsy's 3768, in a mimicking of the "Golden Spike". There is also a short clip of Pennsy's 6100 on rollers.

Notice the last railroad clip shows General Motors and an E unit diesel electric?

Yes, they were rollers placed in a gap under each driver. Can somebody explain why Pennsy did 6100 in as early as they did, after displaying her as the locomotive of the future? They were so proud of this particular creation, then yanked, cut up and melted into oblivion.

Looks like the Minnetonka was faster than the 999.

Interesting that both a steam locomotive (PRR 6100) and a diesel loco (by GM) are billed as the 'technology of tomorrow'. Apparently, both diesel and steam were considered equally advanced at that moment. You can see this steam/diesel equivalency in this ad by ALCO, published in the same year (1939). The ad implies you can't tell steam from diesel -- one technology is as good as the other.

Pennsy loyalists will spout all kinds of nefarious conspiracies and claims; I've heard a few eye-rolling claims over the decades. But a more serious examination will show a few elements that contributed to the early demise:

*The engine's long yet rigid wheelbase did it no favors; it was largely restricted to the straight lines west of Pittsburgh and spent much of its service between Crestline, Ohio (where one roundhouse stall had to be extended to service it) and Chicago, and couldn't be turned on many wyes or sidings;
*the engine was reportedly slippery and hard to start on certain tracks;
* It, along with many other not-necessarily-perfect steamers such as the Q2's and T1's, were caught up in the dieselization programs of the post-WW@ period; as a passenger loco assigned to "prestige" trains, it would be a sitting duck for an image overhaul.

The E-units displayed at the fair were fitted with glass side panels, conventional side panels were installed when the fair concluded and they were prepared for service.

PC