Hello,
Standard 12T vans carried either Van, Vanfit or neither, again down to the interpretation of the personnel applying the livery. This is prior to the implementation of TOPS (Total Operations Processing System) at the end of the1960s which categorised vehicles in to codes with Standard 12T revenue earning vehicles becoming VVV
Paul Bartlett's excellent site shows some of these
Van
Vanfit
Shocvans and other specialist vehicles were allocated to certain traffic. B850498 and sister B850499 were allocated to Tinplate traffic out of Bynea, located in the Western Region and this adorned the side of the vehicle.
This is an ex works image of B850333 allocated to the London Midland Region from 1957 and is found in:
FREIGHT WAGONS AND LOADS IN SERVICE ON THE GREAT WESTERN RAILWAY AND BRITISH RAIL, WESTERN REGION
Author: J.H. Russell
ISBN: 0860931552
The little symbol on the van in "Snow" and on a few of the ones I have done are BR Paint Symbols, they are 12 repeating symbols that indicate the year the vehicle was painted. I have continued this system and the symbols I apply match the current year. Wagon repaints were no more than 12 years apart so there was no repeating of symbols (Apparently)
I have had a look at your images on Flickr and I'm afraid your fish vans are wrong. The blue spot represents a roller bearing fitted vehicle, but you have modelled open fronted plain white metal bearing axel boxes.