Just so you are aware of this going in, finding the 1914 version in that grade range will be exponentially more difficult and more expensive to locate, but you likely already know that.
Keeping an eye on all the auction houses helps, too.
http://www.auctionreport.com is a good tool.
Finally, you might try posting in the BST section here. Just be sure to place your want ad in the proper category (in this case the
pre WWII BST forum for E cards) and put "WTB" in the title so prospective sellers will see the topic. You are free to bump your topic to the top of the list every few days for better visibility.
Good luck. Many times the hunt is more fun than the catch.