Clive,
The 1084 scan brings back memories ! In main workshops we did not have the part numbers entered up, as procedure was that the stores requesition forms ( forgotten that number now), were attached to the 1084's in the job folder. when job was done the repair details were entered in the equipments log book, forgotten that damned number as well (only remember the important details!), to save space, the operation codes were often entered in the book rather than a long saga, if it had been a large job or overhaul. Vehicle examiners wrote the 1084 up and entered it all in the log book on completion. I did do that from time to time, when standing in.
Just remebered something about those codes, the assesssors used them with stock repair times, so you might get them on say tappets for a B60, but actual time was for a Bedford 330 engine, a vast difference in operation time. The arguements we used to have!