Also, they do drive from the DVT to get the train from the yard to Euston, plus it also does ( or did? ) an ecs crew training run to Northampton or somewhere earlier in the day before working 1K39.
Quite often the set runs a full daily diagram on the Birmingham circuit if VT are short of 390s, and it is also used for charters - in these instances, of course, it will be driven from the DVT for half the time.
Having said that, I do wonder why they don't use the 90 to get it back home from Crewe - probably something to do with reducing the hire charge?