I have happened upon an interesting snippet while reading a book on
the Hawker Tempest fighter. (Hawker Tempest and Sea Fury by Robert
Jackson Blandford Press 1989)
'Orders were given for attacks on rocket-firing trains, believed to
be operating on the railway connecting Zwolle, Apeldoorn, Deventer
and Amersfoort, and several attacks were made on vehicle parks
beleived to contain rocket equipment.'
Up to now I had been convinced that the train launched V2 was only a
prototype but the report above does provide an interesting starting
point. Perhaps the prototype was deployed operationally or perhaps a
small production run was made.