Three small side tank locomotives from Sharp Stewart, delivered in 1866. They received a significant reworking in Cambrian days which altered their appearance considerably. All survived to the GWR, who proposed to scrap two of them immediately, but they were reprieved and numbered 1192, 1196 and 1197. They soon received the full GWR treatment above the footplate. The boilers were thoroughly overhauled with top feed added and they were given new GWR smokeboxes, tanks, cab and bunkers. Thus utterly transformed they resumed work, normally on the very weight-restricted Tanat Valley line. One was scrapped in 1929 but the other two soldiered on until 1948, becoming British Railways locomotives and running over a million miles each.

A difficult one to draw, because they all had minor variations and the GWR changed the bunkers twice. Lets not be too precious as to whether every feature in the sketch was on any one locomotive at the same time, but this is intended to show the second bunker enlargement. 
This drawing is very much influenced by the 7mm drawings in Welsh Railway Records Vol 4 - Cambrian Railways Drawings Part 1 : 1853-1892, which has just been published and is much recommended. I've also grabbed photos and so on. I find the safety valve cover rather unconvincing in some drawings and models. Maybe this one is better! This little class has a somewhat higher profile than one might expect due to being the subject of an old school white metal kit in 4mm, and an etched brass one in 7mm. Also, I suspect because they were notably cute in GWR form and more photographed than one might expect.