Quoted from wayout440:Unless I am missing something, all you really have in the proto is red colored boards and some manufacturing handwriting. You don't have the original MPU, you have dented side rails (I had these, from someone dropping the fold down head on the game, correct?) and drilled lockbar - I believe these factors lower the value, not increase it.
Do you have any photos to share of the peculiar inserts you mentioned? Anything else different from the production game on the exterior?
Worse, this proto appears to be wired differently than standard production games and he doesn't have the right rom for it. This is like having the proto TMNT with the different upper playfield or the WWE with the taf style magnets, both of which were missing their original roms.
To the op, good luck getting 3k, but not seeing it. Just because it is rare does not make it valuable. Just because its a proto does not make it worth more than a regular game. If this had something unique to it that was removed from production then maybe (depends on what software it gets stuck on due to it), but you are missing the original roms and going in and modify the prod roms to work correctly is not easy for most.