Your best bet might be to contact Brasseur Trains, one of the forum sponsors, traindoctor.com as they deal in a lot of K-line product and are knowledgeable about much of the K-line parts.
Beyond that you might change your post to be something like "K-line A5 tender help" as that is where the board was originally used. Someone on here probably has one they would be willing to open up and could then tell you exactly how it is hooked up.
