There is no such thing as a "Day Van" in terms of vehicle classification.
A Sprinter Mini Bus without all the seats could be reclassfied as a "Van /Windows" i.e. A Standard Van with Side Glass instead of the Metal Panel.
What kind of MOT does THIS Minibus have? Does it look the same as a Car MOT one, or it is a PSV test (looks like the old style car MOTs, hand written on a Pink Form).
What weight is the Sprinter?