I don't know if John posts here or not, but he is very active on the Digitrax Sound list:
https://groups.yahoo.com/neo/groups/digitraxsound/info
I can only find 1 British diesel sound on Digitrax's British sounds for a Class 8 train. It does not work with the PR3 and soundloder V2 and the SDH166D SoundFX decorder. My PR3 and Soundloader are working correctly. This sound, I believe, is for a SDX decoder. It was suggested by Digitrax I join this group to contact John McMasters to see if the file can be converted for a SDH166D SoundFX decoder. I am a new user to this group so hope I am in the correct place. I would appreciate any help.