For anyone still wondering about or did not know about DRS selling some of their locomotives:
Class 20:
20312 currently is in DRS compass livery, located at Carlisle Kingmoor, in storage since January 2015
Class 37:
37503 currently is in EWS livery, located at Barrow Hill, in storage since January 2005 (not used by DRS)
37510 currently is in DRS compass livery, located at Barrow Hill, in storage since March 2012
37521 currently is in EWS livery, located at Barrow Hill, in storage since January 2005 (not used by DRS)
37608 currently in DRS compass livery, in traffic
37611 currently in DRS compass livery, located at Longtown, in storage since January 2016
37670 currently in DB red livery, located at Barrow Hill, in storage since November 2009 (not used by DRS)
Class 47:
47810 currently in DRS '68' livery, located at Longtown, in storage since April 2015
47813 currently in DRS livery, located at Longtown, in storage since September 2015
47828 currently in DRS livery, located at Longtown, in storage since November 2015
47818 currently in DRS livery, located at Carlisle Kingmoor, in storage since November 2015
47853 currently in DRS livery, located at Longtown, in storage since February 2015
Source: RAIL (railmagazine,com)