It's a million dollar question for a million dollar card.
Some recent postings have talked about the amount of 52's made and some new info on how many were available.
If you read some of these, you will see, even way back then, cards 311-407 were in demand and carried a premium.
I am not sure if the question will ever be answered now, but it does make for some interesting reading.
http://www.net54baseball.com/showthread.php?t=233137