Cable ID?

I have two cables that I've been trying to figure out what they're for. They're both commercial, with molded-in ends. The one that I've gotten furthest on is a video/keyboard cable of some sort, 8-ft long, DA-15F on one end with a box on the other end splitting out into what appears to be PS/2 keyboard and mouse ports (Mini-DIN 6, labelled "KBD" and "MOUSE") and 3BNC R/G/B video connectors. If it was LK-style I'd think DEC, as it is I was thinking X-Terminal, but all the X-terminal pictures I've seen have local keyboard ports and more "ordinary" graphics connectors. There is a part number, 012-1369-00, that when Googled comes up as Tektronix 4200/4300 workstation, but again those don't seem to have the right ports. No manufacturer name. Second has no markings. 9-ft 13W3F to 13W3M, which seems simple enough, but the signals are put through two separate cables and the RGBS portion is broken in the middle and there are two sets of BNC M connectors on them. Other pins are wired straight through. Perhaps connects to some sort of splitter?