Oshiv,
Most design offices had developed their own standards. The ones we had in the EWAU design office were developed over the years. I guess the beginning of it was based on those from the Hatfield and Woodford stables. We had developed our own standard electronic racking type components. Most of these were manufactured in house. Including some forgings, extrusions and sheet metal sections, many turned components and a handful of plastic injection mouldings. We did have access to all of the AGS Standard Part handbooks and the APs you mention in another post.
Goodness knows where this treasure trove disappeared too when the office closed. I was certainly familiar with all the APs on wire locking, O2 installations, bonding antenna installations etc.
Interestingly I was reading a historical paper on the RAeS web site last night about aircraft production in the buildup to the war. It describes the formation of the MAP, SBAC and the need for standard methods and parts.
Best of luck with your quest. The RAeS Library at Farnborough May be a good place to ask. They are very helpful.
As for the demise of the ATP department up at Kentgern house. Very sad retrograde step. Throughout the 80s and 90s I watched the APs you are looking for become less relevant as they were not maintained. The sponsors of these publications either disbanded or did not have the resource, more like.
I am sorry I can’t help
Drag