I am leaning towards thinking fake 75s as well. Counterfeit cranksets? Has anyone here seen that before?
I have a set for sale here in the forum, and this is a picture of the inside of my crankarm. I am not sure if they are all like this, but I would think if they were real Sugino 75s that they would have an NJS stamp on them somewhere - like the ones in my picture do.