What you are saying is that no one knows if it works. I would hate to be the first one to try at a high price and no ground work.
It's pin compatible with Happ Guns.... which also means that it could accept original Namco arcade guns as well.
The thing is.... That nobody here has tried it because of the price.... Availability is not an issue, they will sell you one if you want one.
One interesting point, is that they also sell a USB key interface. Something like Randy's GP-Wiz.... At the same hideously high price as their gun interface. So it's entirely possible that this gun interface could be reverse engineered to see how it works and a much cheaper version produced. This is one I think we should point somebody like Randy GGG at, it's a very possible product line for him.
Best Regards,
Julian (Fozzy The Bear)