What happened was....
Rotala bought the Streetdecks. Most of the Rotala fleet was put into an asset pool, based on an agreed, fair market valuation of those assets. This Residual Value Mechanism (RVM) was created TfGM as a central part of franchising to derisk the process and level the playing field. Those assets were then allocated by TfGM to the incoming franchise operators who, as part of the award conditions, were obliged to acquire those vehicles allocated to it at the stated value as provided in the RVM.
So essentially, they agreed that 20 Streetdecks were worth, for instance, £4m at £200k apiece. That's in the valuation in the RVM, and that a tranche lot had the 20 Streetdecks allocated to it. Go North West and everyone else would have (or should have) put the £4m valuation into their overall costings with GNW paying Rotala on transfer - I don't believe that there was any capital spend or financing from TfGM unless someone can advise.