The vehicles were of a high-density layout, built to drawings supplied by Derby based on their 116s. Most were delivered without marker lights, giving the front a rather plain appearance. It seems (based on note's on the Diagrams) that the last three pairs of power cars were delivered with marker lights. They were added later to the others in the late '70s / early '80s.
They were more or less identical to the BRC&W Class 118s, the only obvious difference was that the top of the 4-character headcode box in the roof dome *generally* had a flatter top than the Birmingham build. However the first few 117 sets had the 118 style curved top so identification wasn't straightforward. If a set had a flat top indicator box, or was in unlined green livery, it would be a 117. Otherwise it's pretty tough to tell them apart!
Drivers cab handrails started out as having a dual purpose of being hollow and acting as the drain for the gutters. These were always blocking so a nomal handrail was later fitted.
Originally they had 'square' (or 'cut') buffers - large circular ones that appeared to have the top and bottom cut off. Later other types could be found such as oval or large round ones - which 51332 had fitted on it's first works visit.
The sets were ungangway when new. There was through access inside the vehicles - the interior partitions having doors - unlike some high-density vehicles. Gangways were added later, with at least four sets having them by 1965, allowing them to be strengthened with converted hauled stock or other trailer. From about 1968 the rest had the gangways added for 'Paytrain' operations. The gangways were the GWR 'suspended' style, as seen in the image of 59517 taken at Tyseley open day on 10/4/87 by Malcolm Clements. Note also that it's a now a TSL, some of the centre cars were downgraded to second class only.
The exhausts starting out as being the Derby type joining together in a box at roof level, this can be seen in the works images. There were later changed to the normal individual style.
Inside, the second class seats began with maroon with tan headrests. The floor covering was green and the partitions were in light tan coloured 'wood grain' formica. The drivers cab seats were green.
WR AWS (ATC) was originally fitted, in the '70s they were dual fitted with standard AWS and then the ATC was removed.
The power train was pretty standard, Leyland 680 engines, R14 gearboxes and F239 final drives.