Thor:
In answer to several questions:
The D&S didn't attempt to disguise the 486. She made several trial-breakin runs before her official debute on Saturday by pulling a few assorted cars.
Her tires look new--plenty thick and, though I didn't personally talk to the crew, it appeared there was not much short-cutting if any. Her valve timing sounded a little off but this could be corrected with a little fine tuning.
Lastly, I would guess that the air pump got involved in an exchange-rebuilt program and the 476's was borrowed to get her going.
All in all, she put on a grand show through Saturday.
Les Clark