Found a schick krona I'm guessing out in the wild. Picked it up and cleaned it up. Seems shave ready so we will see. No idea how to date this razor though it does have some numbers on the bottom.
Congrats! I'm not sure how to date it either, but you'll find some great info in this thread
http://badgerandblade.com/vb/showthread.php/361103-Schick-Krona-Questions