I really doubt they were fake, lets not pretend everything aiwa and sony made are gold, just because its vintage doesnt mean it cant be crap. That particular model is just that, crap.
The point is there is just no way to tell. There were so many fake back then that some people thought they were truly owning the real thing only to find out they are fake years later, if at all.
In fact, just a few years ago counterfeiters get so good that Shure engineer can't tell just by looking on whether the transparent SE215 sent back for warranty was real or not.