Mike Tyson's punch out with adaptor?
I came across this thread that mentioned me at one point last year but I did not see it earlier.
I can't see the pics that were apparently posted but the idea that Nintendo made a version of a five screw MTPO with a Famicom adapter does not make sense for many reasons, some of which were mentioned in that thread. But most of all it is clearly someone's tinkering with it decades after the fact since the Famicom boards used in NES cartridges had a strategically-place hole where the middle screw on a five screw cartridge case would go and hold it in place while regular Famicom boards of MTPO do not have that hole and a hole cannot be drilled in that location on the board without ruining it. That is why this cartridge is described as not having a screw in the middle hole at all.
When researching the possibility of a five screw MTPO with a Famicom converter in it I quickly discovered it was an impossibility and, since I have a weird obsession with collecting everything related to this game, I thought of trying this myself just to have something different (as I've done with making 5 alternate labels that I put on new colored cases using original boards whose original cases had severe damage). But it simply wouldn't work with a center screw so I gave up on the idea.
That being said, I would like to have something like this if whoever did it did a nice, clean job. But it would really only have any value with a weirdo like me because it's not something that actually existed via Nintendo.