Dear Richard,
To get an impression about the "Engschrift" (narrow type) DIN 1451 check here:
http://www.enkel.museumseisenbahn-hamm.de/prdin.htm
The description is about the stencilling at the Reichs Railway from 1906 and 1932. if you click "Hinweise zum Schriftsatz"
http://www.enkel.museumseisenbahn-hamm.de/hinwpr.htm
youŽll get some hints for stenciling and the distance between the different letters. Maybe this will help you further.
Regards
Roland