01200 pairing change.

This recently appeared on NE Transit:

"Car 01263 is original car 01281 and car 01281 is original car 01263. Cars were renumbered and swapped mates 08/2014."

What happened to cause the swap?

Two cars were OOS long term. Luckily, one was an A car and the other a B car, so they could trade their mates to make a good deuce. Rather than having a mismatched pair they renumbered the B car to look right with the A. Previously, mismatched pairs were allowed to run mismatched (01450/01455 at Seashore, which ran that way in service, for example).