Agreed Bryce What a wonderful piece of history that Thomas has posted.
I think that the 639 9004 may be transcribed wrongly from 639 0004 as the sister car 119 300 932 (S M 2929) is recorded as having engine 639 0010

Thanks Thomas for posting this

Bryce
that reminds me that there are probably some things that i need to update in that thread when i get the time