Oh in that case fair enough. A few select members have also done this in the past for similar reasons, either by creating certain scripts to 're-insert coins' upon a rom load or by writing an associative program to interact with their front-end and retain the coinage display in the FE itself. I understand what you say about your system and inevitably it will have flaws but it's a nice system to retain for yourself, particularly with the nice addition of the LED display.
- Beretta -
Yes of course it is possible to quite easily mask a cabinet's true origins if no-one sees the boot and you run one game. Most would not know the difference, even if a few of us here could probably spot a PC-run game in comparison to an original PCB-driven system (things like the occasional sound clip or frame skip being the most obvious giveaways).
Your observation about potential profitability however couldn't be further from the truth. Whilst most original games in their own right would mostly go ignored in many different locations (a store, a pub, even a modern arcade), a shiny, resto'd or replica cabinet with one game might pull enthusiasts in the right setting. More likely though, is that if MAME was somehow made to accept universal coinage and retain that whilst switching games (either by a Neo-Geo type switch or by use of a custom FE), this could be of huge appeal to some businesses as it could offer so many gaming choices (and hence appeal to more people) in just 1 cabinet.
You may not think it but it is more common than you think. We alone have several requests a month for this type of machine from various sources including these: chip shops, pubs, clubs, casinos, a recording studio (?!), children's playgroups, pool halls, rec centres. We get these despite the warning/disclaimer we post on our website saying these type of requests will not be entertained, and the fact we do not advertise anywhere focused at commercial customers. Most requests I just ignore as they know what they are asking for is illegal, but for those who are obviously naive I re-iterate the point by replying and telling them both the legal issue and that the software is just not designed to operate that way. It's enough to stop them asking and also usually stops them asking elsewhere or seeking those multi-game PCB cabinets. At the end of the day it's their neck at risk, so it's doing them a favour as well as us by steering them away.