Those are some fine pieces there bro...Dimaggio is harder to authenticate because his style has been all over the map for years but I like both of these as AUTHENTIC...they don't get much better then this..
Well I posted the balls on ebay and did a PSA/DNA quick opinion. And for what its worth, this was the results:
Your Request for Item "Joe Dimaggio Autographed Baseball", eBay Lot No. "261075824456", opinion was rendered at "7/31/2012 3:55:54 PM" and the result was:
Response: "Likely Genuine"
And
Your Request for Item "Mickey Mantle Autographed Baseball", eBay Lot No. "261075824456", opinion was rendered at "7/31/2012 3:55:50 PM" and the result was: