Although this does not pertain to long range, I inherited an Aimpoint 2000 on a Ruger MK I from my Dad. This model was discontinued around 1989. It does not work. It is in great shape outside and in (no gunked up battery compartment), like brand new, and I would like to find a manual, better yet, a schematic for it. I have looked online with no luck. I have disassembled the side tube and all looks well. There are two wires going into the main tube and I don't know how to get in there. I don't want to mess it up. Any help would be appreciated. Thanks.