Here is the gas tank wagon after weathering – I have really struggled to get some decent photos that show the colours on this. Daylight seems to have washed it out to a grey colour when in reality it very much has an uneven brown cast to it.
All the photos I have in my LNER books show that gas tank wagons got very dirty but without exception (in the photos I have) the lettering is clearly visible.
My weathering mix was made up of the following Vallejo Model colour range, all diluted for spraying with Tamiya acrylic thinners.
I started with a base of a more brownish colour and spraying from 8-10″ away so their was a bit of splatter giving texture as well as colour. Then I added more of the greys to the mix and went over it again. I used a small brush and meths to uncover the lettering before adding another light coat with the greyish mix to blend it in. I used some antique brass to paint the handwheels before the weathering, again easing back the gunge with a small brush and meths.