Doctor Restuffin'
I had a "dead" humbucker on a junked guitar I bought back in February. I also had a box of miscellaneous pickups I've been hoarding since last century. I found ONE that has the screw pole pieces in almost the right configuration, so I pulled the shell apart and did my best to re-stuff it with the new coils.
You can see how the screws are just a bit off, but I'm going with it.
The coils came from a unit that had a threaded bottom plate, while the new housing didn't. My solution was to scrounge up some nuts to hold them in place. I also managed to add a strain relief for the cable.
I could not get the ground to solder to the case, so I added a bit of braid as a grounding strap and soldered to that. (Visible in the lower-left of the photo.)
I had bought a new set of humbuckers, but they did not fit the over-sized frames or routing in the guitar, so I had to "Frankenstein" this half-assed solution.
Here's the guitar in question. The problematic pickup is the one in the bridge position.