In the last year, I have moved into postal history. By far, the most interesting classic covers (in my opinion) are the various international usages. This is my top acquisition to date (courtesy of Siegel Auction earlier today).
With all of this build-up, I hope that the backside has something to offer....quite honestly, I bid on this solely on the merits of the front of the cover. I have yet to examine the cover in-person, and I'm as clueless as everybody else as to the contents (if any) of the reverse side.