The XK1 uses a FATAR keyframe, so you should be able to find a pretty close match for the LM. Using an old XB2 is a good idea though and if it has version 2 software you can use the drawbars to control the lower voicing. Even an XB2 with a MUSE fault (distorted sound) will be fine - and dirt cheap on ebay if it is faulty. If its a version 1.0x you can always add the V2.0x software.