[MtnSpur]

Without a clear picture it's hard to diagnose but there is no "bushing" associated with the firing pin(s). FOUR components are 1) Front firing pin 2) Rear firing pin 3) Firing Pin Spring 4) Firing pin Lock Pin.

 

[MtnSpur]

Sounds like it and we all learned something. First the "insert" on the breech face isn't diagramed with the firing pin "assembly" (I use assembly due to the 4 parts). Perhaps it is in blueprints as part of the slide as shown in Brunner's book on Page 8 (Fig 6) there is a callout for a ".218-32 NS-3" exactly where that piece would be. Interesting stuff. Unfortunately the parts list isn't included, due to proprietary stuff, I'm assuming

 

[MtnSpur]

The recoil plate was considered an integral part of the slide, and would not show up........

While it may be considered as such there is a blueprint of the slide and the dimensions and then an assembly drawing/blueprint with a detailed parts list. I strongly suspect the assembly drawing will have the "recoil plate" as we're now referring to it, as a part, since they had to assemble that into the slide. The details of assembly are then a separate document that would typically been found in manufacturing, separate from engineering. Each and every piece of the pistol HAS to have a part drawing replete with dimensions and tolerances. I spent over 30 years in design and engineering specializing in CAD/CAM, though more on the CAD side of the business.

To recap: Part drawing, sub assembly drawing (occasional), assembly drawing with parts list(and related part number to reference BACK to the part drawing) - all at the design and engineering level. You hit the "floor" (manufacturing) and that's a whole other world where assemblers on each station have their instructions, all coordinated like a ballet.