I think that if any bit of the WCML should be added to TSW, it practically needs to be London Euston - Birmingham. This is the main stomping ground for the Pendolinos, and soon GNWR will begin operating Class 91s and DVTs along there too.
first of all you're a beg and you don't deserve the 390 if you beg this much second of all this is my opinion: i would pick WCML London to Birmingham with additional Watford DC and Abbey Lines utilising class 390, 221 ,350 377,319 with the option of adding the Bakerloo Line 72 stock from queens park to harrow and wealdstone and the freight trains will be class 90, 66, 47, 86,87 and 92 with the option to buy a Caledonian sleeper reskin for the 86,87 and class 92 with the addition of BR MK2-F coaches and MK3SLEP