Isn't it the case that these airframes were ones which became surplus to requirements at MFTS Shawbury when it was realised somewhat late in the day (the cabin size issue) that they had too many 135s and not enough 145s. Under an apparent MoD/MFTS face-saving arrangement more 145s were procured with the surplus 135s suddenly and conveniently meeting P. MATCHA's requirements. Given that public money has funded all this, it would seem quite appropriate for the airframes to go to NPAS to address some of their woes.
P.