It's a long time ago but I think it would be Humbrol light earth let down a bit with thinners. Precision Paints do / did a similar sleeper grime too

It's 7ft long by 10in wide.

@@DavidGander590 Thanks David. Two 3' 6" boards at just 10" each is what I'd call very portable. By coincidence I searched and found your original article this morning in a trawl of the 009 News library (April 99 for those who may want to read), an interesting start for the layout, something I'm sure all modellers will have suffered at some point, but then a Dad inspired 2nd board and, as they say, "the rest is history". I'm now hoping to see this layout in the flesh sometime - had I known of it, I would have trekked from the south coast to MK just to see it.

It is a Golden Arrow whitemetal and etched brass kit if the Welshpool Earl and Countess. This was built by a friend 30 years ago. I believe the kit is still produced in short batches from time to time.

Thank you, by the way do you have any idea who would have this kit?

I'd try Golden Arrow Productions via their website. I think they only sell direct.

They are whitemetal castings by Dart Castings. Still available I believe.