The hire of DRS class 37/4 and Mk2f (odd one or two e's) is to continue until July 2019 if the franchise agreement is to be believed.
Locos modified to work under GA Safety Certification are: 37401, 403, 407 (when delivered), 419, 422, 423, 424, 425 and 716. I believe 401 is the only 37 not to...