Many thanks for all of the positive (nice) comments - it's amazing the quality of the photographs you can get with an iPhone.
Jim - my skills and confidence have yet to achieve a level where I start attacking rolling stock

. The fish van is 38-578 Bachmann 10 Ton Fish Van BR Bauxite (Late) (Weathered) - that is how it came out of the box - it says "Billingsgate" (naturally!) on the side of the wagon, and there is some indecipherable writing on the other side. I have not looked, but you might be able to get a pen (?) in Hobbycraft that has a very fine tip and writes in white - they seem do do most colours nowadays. Obviously on real wagons this would have been chalked on. Barry