Do you have any specs for those old University Sound drivers? I'm not familiar with them, but most drivers similar to them from that period had very low X-max and probably wouldn't like being eq'd. If they have a highish Q to begin with, they may not even need eq'ing. Without knowing the fs and the Qts, it'd be hard to figure out the correct baffle size. Fortunately, it's cheap to buy a sheet of 1/2 inch MDF and experiment.