Posted By: 
HarryThanks for the additional comments.
Based on all of your comments, I have made the person an offer for the whole lot under the following terms:
1. I will pay a deposit upfront.
2. He will send the cards.
3. I will send them to PSA at my expense. 
4. If they come back slabbed, I send the rest of the money.
5. If they are deemed reprints or altered, I send back the Ruth and Gehrig and keep the rest of the cards for my deposit.
I sent this to him and I'm waiting for a response.  It seems like noone has doubts about the others cards, just the Ruth and Gehrig.  So the seller really has nothing to lose in this deal.