I got a "pc turbo" in a lot of a bunch of consoles and controllers from yahoo japan a while back. its definitely aftermarket or clone.
it has NES style rubber membranes and not pc engine ones which is kind of interesting i guess.
i think mine has a bad cable though as it currently isnt working right. im not sure what the switch on the back is for
edit:
i just checked and one pin does not have continuity back to the connector inside the controller. im not sure if its really worth it to attach another cable, but i may at some point.