And the debate continues.....
I really wish that I knew the full story of all of these different guns. From my experience with these guns, which is a decent amount, the images on the Riemen site are absolutely correct in that the black plastic and "red" (orange) guns were made for the PC while the black rubber guns were made for the VS. The plastic ones can be converted to work on the VS., but because the rubber ones are virtually impossible to open without destroying the gun, they cannot be used on the PC.
But where do these pink and blue guns fall into the picture?? I have read that they were originally made for the dedicated Hogan's Alley machine, but some can be used on the Playchoice!?!? The pink and blue colors remind me of the old Konami Justifiers that were made for the SNES, which would make sense since there is no Nintendo logo on them, but that would scratch the Hogan's Alley theory. And as far as I can tell the insides are usually the same. The trigger assemblies are always the same, but I have opened a few blue ones that have different sensor cards in them that I cannot seem to get to work on the PC.
One thing is for sure; with exception of the black rubber guns, any of the guns can be reasonably easily modified to work on any Ninty machine.... But what is the original intention for each of these guns. I keep reading debates on this subject, but never with any resolution. Hopefully someone can shed some more light on the subject.