XD9, as for finding an emitter that will fit, since the EDC was custom designed for the Luxeon emitter there really isn't anything off the shelf of which I am aware. For my mods I would up fashioning something out of a trimmed MCPCB with shims underneath.
I don't have any photos but think old air force insignia, with a large round center and two narrower rectangles coming off of each side. Then I used some copper shims under the cut-down MCPCB to get the height right for the reflector/focus, and to provide a thermal path for the emitter heat. My modding objective when it comes to old classics is to always leave it as original as possible; otherwise one could just bore out the pill and drop an off the shelf Cree MCPCB.
Without seeing the previous mod I suspect it ran afoul of the circuit trace hazards from trimming and the emitter got shorted. When trimming the MCPCB one must be mindful of any exposed circuit trace edges on the board; in particular any shorts between the +pos and the MCPCB aluminum/copper board itself. We're talking fractions of a millimeter separation that are easily accidentally bridged/shorted. In addition to avoiding cut circuit trace edges as much as possible, I always insulate any trimmed edges with epoxy, such as used for re-coating circuit boards, as an added precaution.