In 2008, collector-dealer Mike Wheat issued his own set of Deadball Era exhibit cards with postcard backs. They are
very nice. He has full sets and series. There are also a few singles available. Here is the eBay link:
http://shop.ebay.com/i.html?_nkw=dea....c0.m270.l1313
And, has been previously mentioned, TCMA (and Mike Aronstein's earlier effort, SCFC) issued some nice reprints of early Exhibits.