Thank you ever so much, that's really hhelpful. My mid 1970s period can support a nice mix of grey and brown wagons then.
Again, thank you. I really appreciate the input.
That's fascinating. Just like above, I'm really grateful for your help. I've just returned to the hobby, and am very keen to learn, but want to start off on the right foot and get a prototypical mix of wagons for my little layout.