Ok, so I wanted to let you know what I ended up doing. I decided to take the "scary" route and turn my 57 classic+ into a 4 conductor pickup (and also move it from a tall frame to a short frame for the super sport). These were all brand new pickups I was working with and this was the first time I had taken apart (expensive) pickups...
I replaced the regular 4 conductor 57 classic (that I had installed a month ago) with my new hybrid 57+ and... nothing. It worked just fine, but it's just that I could not hear any real discernible difference between the classic 57 in the neck and the 57+ in the bridge. I was stunned and was starting to become distraught.
I then decided to put the original Dimarzio back in the bridge. It DID sound different. It sounded ok, but not great, and certainly not better than the classic 57 in the neck. The thing that I was hearing in the neck that I really liked were the beautiful harmonics I was getting when I was playing D and G chords. It was very open and 3D sounding while the dimarzio was more focussed.
After this, I was considering giving up on my super sport, driving 7 hours to a music store in Italy that sells lots of vintage Les Pauls and getting on with my life and guitar playing.
I've had my guitar for 3 years and I LOVE MY SUPER SPORT. After playing it, I cannot go back to playing any other brand. The simple truth is that Music Man guitars are the most comfortable and playable guitars in the industry.
I decided to try one more thing before I gave up. I had a Seymour Duncan Slash pickup (brand new and slated to go into another guitar). I turned it into a 4 conductor pickup, put it on a short frame and stuck it into the bridge and there it was. Beautiful tone, beautiful harmonics, great match for the classic 57 in the neck.
I was happy with it but I wasn't done yet.
I was starting to gain some confidence in taking apart and rebuilding the pickups so there was one more thing I wanted to try. I wanted to match a bobbin from the (unremarkable) 57+ and the slash pickup. So I took them apart again, stuck it in the bridge and... It was pretty unremarkable. So once again, I ripped the pickup out, rebuilt the slash pickup and put it back in the bridge.
And now I am satisfied with the sound of my guitar.
I've attached a picture of my guitar with my new marshall DSL40CR. What a killer amp. If you look closely at my super sport, you will see that the creme bobbin (with the screws) instead of the black is closest to the bridge. I guess that's the way Seymour Duncan rolls...