In the October issue of Modern Railways there is some information on the TfW rolling stock.
It is reported that:
Class 197s 77 units on order, 32 units accepted by early September, ongoing into service one per week
Class 153 30 in fleet, 26 in service, 13 to be retained long term for HoW etc
Class 150 38 units in service, all to leave by mid 2025, including 2 from Northern.
Class 158 24 units in fleet, all in service
Class 175 27 units (2 and 3 cars) 17 in service, all to go by end 2023
Mk4 and 67 8 x 5 car in fleet, 6 x 4 in service