They are beautiful pins, no doubt about it.
I had worked on some cleaner schematics for it a while back, never did get them totally "done" though. Here's a link to where I had the latest versions posted. Eventually I'll get back to it, but it wasn't my machine I was working on and I got away from doing the drawings when that project ended.
There may be a couple mistakes in there, and let me know if you find any so I can correct it.
http://www.siegecraft.us/the_siege_blog/blog/2011/04/atari-superman-pinball-diagrams-in-progress.html
Leon Borre has some board repair tech info on his website, plus a diagnostic ROM file
http://www.flipper-pinball-fan.be/
Interesting design for the boards in these things. Each lamp or switch has a dedicated wire coming back to the boards, no 'matrix' layout at all. I also don't believe you can use LED's at all in them, they 'warm' all the insert lamps with a small current. You'll notice if it's dark in the room, that all the inserts always appear to be just barely turned on. That's normal. It helps longevity of the bulbs, but if you put an LED in it, the thing will never turn off.
-Hans