But, the problem here doesn't seem to be the choice of train, but the business model. *Lunatic*, n. One whose delusions are out of fashion.
The leased Eurostars' Northern excursions were a relatively short episode, lasting from 2000 to 2005. Check some photos on RailFanEurope -- here is one, with a train in GNER colours:
*Lunatic*, n. One whose delusions are out of fashion.