wherefor is just a variant of wherefore (there were a good many others which have gone away heretofore). WS was a notoriously bad speller -- or at least inconsistent; to wit:

Against whose fury... The awlesse Lion could not wage
the fight. -WS, John I

Insulting Tiranny beginnes to Iutt Vpon the innocent and awelesse Throne. -WS, Richard III