SN9463 sold in 2012 on eBay for $1,684
Looks like it was kept in a dsuty basement for a long time however the seller assured the cabinet was in good condition. He also noted the monitor and power supply are not original however everything else was.
The seller says it belonged to his father's friend who had recently passed away. He adds: "I saw him turn it on and it worked about 8 years ago, He actually used an old Nintendo RF switch to connect the audio/video to the replaced monitor (just a tv). I do not know how he did it and I don't want to try so I don't damage anything. Anyone who knows about arcades should be able to get it working pretty easily."
This might also explain the unusual white power supply.