I've gone hunting all over, and there isn't a named description of the connector, other than round-pin Type U connector, which doesn't seen to show up anywhere else except in that document. What you could do is replace the connector there with an IEC 320 C14 socket (like the ones that were used in the later versions of the 745). Then you just get a standard IEC 320 C13 cable and connect it to the device and you're done. Looking at the pins, they are in the same positions as the IEC 320 C14, but using round pins and an oval socket. You'd just have to verify where the three pins go power-wise, and the maintanence manual should show that somewhere in the schematics. I did see one plug of this type for sale online (it was listed as being used for older vacuum tube equipment, but it was already sold when I found the reference).
Section 2 refers to the pages numbered 2-XX in the manual.