I haven't come across any works pictures taken by Pressed Steel, there seems to be very little relating to railways in the company's archives held in Paisley library. However British Railways often photographed the vehicles it received from private builders and so the following images existed in the Swindon Works official works photographs.
The National Railway Museum at York has the surviving negatives from the Swindon Works photographic collection, and prints may be obtainable from them.
All recorded as taken on 10 December 1959
I don't have copies of these two:
Negative 5CR-149
59484 view unknown
Negative 5CR-150
59484 2nd class saloon towards centre
I don't have copies of these two:
Negative 5CR-153
51332 Interior towards cab
Negative 5CR-154
51332 Interior towards rear
These are all recorded as being taken on 25 February 1960 and all were 51334.
5C-305 Cab (interior)
5C-306 Cab (exterior)
5C-307 No.2 engine
5C-308 Underframe details
5C-309 General underframe view
5C-310 Final drive isolator
Summary
Orders
Description
Gangways
Diagrams
Works Photographs
Numbering & Driving Inst.
Set Numbers
Liveries
Operations
Refurbishment
Non-Passenger Use
Images
Details about preserved Class 117s can be found here.