(not trying to derail the thread but)
speaking of Sugino Mighty, i also hear Suntour's Superbe crank from the same era (namely CW-1000 model on
this velobase page)
was also manufactured by Sugino not by Suntour, with literally identical material and quality to the Mighty.
is it a trustable info?
from what i see in terms of the Campy-copied shape/bcd and how the marquee is engraved in the middle of the arm,
it sounds quite reasonable...