Cards from that era are worthless.
Cards from the 70's and earlier are really the only cards that shops will want. Problem is, there's so many cards that were printed in that time, and so many people collected them, that there's nothing rare. Unless you have some mis-prints or something out of the ordinary, dont even waste your time.
Because of this, I dont even try to sell any of my cards. I figure I'll hold on to them until maybe 2040 or so. That should be enough time to thin out the numbers..