Since this question first came up I've done a bit more checking: The original XM-1 MIDI module had an 8-pin DIN output, as does the new XM-2 module (with the XK-3 sound engine), and the current XK-1 keyboard.

Available Adapters:

XM-11 - DIN-8 to 11-pin

XM-22 - DIN-8 to 6-pin (6H, 122 type)

XM-47 - DIN-8 to 6-pin (6W, 147 type)

XM-97 - DIN-8 to 9-pin (825, 760, 770, etc.)

XLD-11 - DIN-8 to 11-pin (new model for XK-1, etc.)

(from Harvey Olsen)