Another early bird this one. These two were the first GWR built 0-6-0T, and belong to the Gooch era - built in 1860. They were quite small engines with 4ft 2in (or possibly 4ft) wheels. They were fairly typical Gooch designs with domeless boilers, raised fireboxes and Gooch valve gear. They had inside frames, small side tanks and a well tank under the bunker. When renewed in the 1870s, they were turned out as members of the 850/1901 classes, so it is probable that no significant parts were reused. They don't really seem to feature in the general GWR 0-6-0T evolution. 

I rather fancied doing this one, but the only source I could find was the E L Ahrons drawing which has been reproduced in several places, notably Holcroft and RCTS. I haven't found any photograph, which isn't really surprising given their early demise and probable low profile. Curiously Ahrons and Holcroft (the latter following Ahrons I imagine) refer to the 'class' as being 91 & 92, but as seen elsewhere in these pages 91 and 92 were 0-4-2T built for the GWR by Beyers.

The valve gear was a particular issue. I didn't think I could leave it put completely, so I tried to make some sense out of the lines in Ahrons drawing against a copy of Stephenson's gear from another locomotive and altered it for what I figured were the visible differences in Gooch gear. I call these drawing sketches since although intended to be scale I can't guarantee accuracy, but this one is perhaps more sketchy than most.

Which brings me on to livery and lining. I omit lining. It's shed loads of work, and scale lining at this sort of size disappears into anti-aliasing anyway. Plus it tends to obscure the underlying shape. But this one does look a bit bald without it. As for livery, well according to GWW dark holly green, so I picked a dark holly green from a number of choices available on the net. But like most colour names its a broad church. Who knows!