yegbert - great info. While I don't know much about this topic it has certainly sparked my interest since I am lucky enough to have a couple of these pickups.
"Are the female threads those screw into, integral to the bobbins? It looks that way. Are those bobbins plastic?"
plastic for sure - possibly a nylon. They are threaded directly to accept the pole pieces.
"I find it a bit of a surprise the threads on the polepieces are metric"
me too! I thought they would be 1/4-20 or such. I am glad I had a thread gauge as I would never have guessed metric.
Do you think the thread pitch is critical to reproducing the pups?
I would sure like to find some nice shiny new covers for mine as the chrome has been corroded badly on my original covers.
(We do like SHINY NEW CHROME don't we Telenator

)
I'd have mine replated but I'm worried that the FENDER engraving would be lost. Ideally I could find some new covers to put on the pups and put the originals aside for safe keeping.
Steve