Only 3 DVTs are needed for daily service, one is always kept as a spare for months at a time along with a spare 1st class, bar coach, EGV and 2 standards.
Things seem to be moving along recently as I saw 2 Enterprise 201s on standby at Connolly on Thursday night, it was too dark to see their numbers but one had not yet been fitted with the new connector.
The whole project is a mess at this stage.