Thanks to those who appreciate my comments.....
Regards the spring... properly installed (smaller end TO the plug), it provides an additional grounding path to the top shoulder of the metal base/body of the plug. Personally, I think it is handy to keep.

Also, FYI - I am no longer following this thread as I have sold my DL's. If anyone needs any info, however, I would be happy to help.

Tim - absolutely outstanding documenting of the service assembly. Well done. And thanks!
See ya'll around other threads.