The games with specific topper types are leased games. The techs will usually remove the software and use the cards for other purposes (even used to make a machine parts complete) and thus become available to the secondary market. According to the contract with lease games, the games are supposed to be destroyed after the lease ends. So a lot of these boxes end up getting crushed, but some are just thrown away and find their way to the hobby by enterprising dumpster divers. They can be found, but they are rare. The same case is true for Wheel of Fortune type games, but they are more plentiful so more are around. If you could go back in time, you would find maybe one or two topgun machines in a casino, but several banks for WOF games. Even with so many, the WOF games fetch such a premium because it is difficult to get a fully working machine without having to do some clever part digging.