A second ex-Tiger Centro has emerged today - 1534 (YJ58 FFO) appeared on 15s mid-afternoon for a Stockton-Thornaby-Roseworth trip (end of the running board)
Arriva North East 1534 (YJ58 FFO) by Tony Kuy, on Flickr

Possibly due to the entry into service of 1534/5, 1914/22 have left Stockton depot. 1922 is now at Darlington and has been on X66/X67s - working two different boards (it overheated after a single round trip on X66s early afternoon before being thrown out on their late board at teatime)
Arriva North East 1922 (W83 PRG) by Tony Kuy, on Flickr

1914 is reportedly off to Durham