Well I'm suggesting using the mark2s precisly
because more DMUs are not an option until (hopefully) 158s are released from Scotrail in 2015/16.
Full DDA compliance doesn't really matter until 2020, and I've already said that I expect more modern stock will be available to replace the mark2s before then.
Correct, nothing stops ATW from using old build stock it owns, within the equalities regulations there are exclusions,which seem to be forgotten.
Like all Acts & Regulations it is up to the owner or whoever that supplies the service to decide, few read the guidance notes.
plus
http://www.arrivatrainswales.co.uk/Timetables/ 14th May is published