I got a '51 recently just to mess around with... well I traded for an Alnico II Pro recently and I was all ready to throw it in tonight and just wanted to be sure I was clear on something... Now, you probably need to know that it has a push/pull on the Volume that splits the coils AND there's a rotary 3 way selector... I took a pic of the 'goods' for reference. The green cable that has a red/white/black cable coming out of it is what we're looking at for the humbucker that's currently installed.
Now, going off of this diagram I think if I ignore the neck pickup (since I don't need to pay attention to it right now) that I can assume that I put the bare/green together and they go to ground (replace the black wire above). Then I put the red/white wires together and they will go to the volume push/pull pot. (replacing the red wire above). Then lastly I can replace the BLACK wire from the SD pickup with the white wire above (going to the rotary selector switch) and that should do it.
Are my assumptions correct or am I dead wrong?!