Our suite got new carpet this weekend, and as I was moving the machines out of the way I pulled apart the serial adapter. The RJ-45 clip held fast, and the metal body was screwed tight to the machine - so the metal body pulled out of the plastic shell, and all of the sockets pulled off of the interior pins. It pulled away at a slight angle, so I can tell that pins 1, 2, 3, 4, 7, and 20 were connected - they're bent just a little.
I found this page, which includes pinouts for RJ-45 adapters to DB25 and DB9... but they specify 8 wires, and the adapter I broke only has 6; also the color scheme is different. My adapter is labeled
3230289-02 "SUN"
but I have not been able to find whose part number that is.
I'm going to try to transpose those instructions from 8 wires to 6 and hope it works - but I'm hoping that someone out there has seen (or HAS?) an adapter like this.