1977 marvel super heroes card game

Hi Guys,

I have recently cleared out some old toys and games and came across a
card game similar to the 'top trumps' games. It is called 'Super
Heroes' card game and was manufactured by Marvel comics int in 1977.
It features 40 cards covering heroes and villians, and the back of the
cards shows the face of Spiderman. I have been searching the net for
any info regards to value of this set but the only thing I could find
is a referal to them at this site:

http://daredevil.dreamhost.com/merctoys.htm

where they appear first in the card game section.

If anybody has any info I would be most gratefull,

Many thanks,

Jason