If you have a crew in an inspected, brake tested engine ready to rock at Race Street, it takes a little under an hour doing single lite engine speeds to get to Paoli. Given that the odds of an inspected spare being ready are not necessarily high, particularly on Christmas, the actual time would be closer to 90 minutes once the crew heads out to the engine, does the brake test, and takes off. That, of course, is after management has decided on the suitable course of action, which is a glacial process at best.
I have no doubt that putting the passengers on 43, two hours behind 663, was the quickest option, short of rectifying 663's issues.
"It's not even a railroad anymore, it's a circus act."