I just sent a message enquiring about the deck through the Gallifrey One site... I'll let you know what happens!
I sent them an email a few weeks back, still haven't heard back. Along with their facebook page and a few other Doctor Who internet haunts. I hope you fair better than me as I have pretty rotten luck.
For the Secret Weapon deck I'm looking for, the way to distinguish the different versions and not be swindled are as follows: Vietnam will have U.S. Playing Card Co, Cincinnati, OH listed on the front. Desert Shield will have this as well but will state Desert Shield on the other side. The new reprints they did just have U.S. Playing Card Co with nothing else since they're not in Cincinnati anymore. The Vietnam decks are quite pricy as they are understandably quite rare. Desert Shield ones can be had for $25 all day long via eBay. I got my pack from a friend that was there. The new ones are something like 3.95 and can be bought from bicycle directly.