New Shipping rates....old PSA sub forms?

I have a stack of the "old" PSA submission forms now with the "old" postage rates. Can these not be used if I figure the extra shipping and just add it to the total? Or do I need to order completely new forms?
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Saturday I sent out a sub using an old form, factoring in the new shipping costs.
If they dont accept it Im in trouble. There were cards I wanted to have graded by the award deadline.
-- Yogi Berra