Im still under the impression from sources un-named that the VTTS lot could have had more engines and carried on flying to the planned end date IF they had stumped up the cash to RR
Unfortunately there is no truth in this at all. VTTST had the last eight Olympus 202 engines that were acceptable to RR; it was the lack of willingness of the latter to support them post 2015 (due they said to a lack of sufficient competence within the company) that grounded the Vulcan.