Dart 1655 and Prestige 4044 made appearances on the X3/X3a today (both also working peak time X4 short runs to Easington and Saltburn respectively)
Cadet 1917 appeared on the 15 today (not completely rare) while 1924 appeared on 9/27a as well working the last 17 (the more normal home for SB120s) which is meant to be Pulsar. Here's a selection of photos of it from Overfields this evening on its last 9 (and the last 9 back into Middlesbrough from the estate) before working the 17.
RE: Arriva North East - Rare and Odd Workings