The good Captain Martin Campbell ran his own philatelic empire from Sussex offering "free! 30 USA". Sending in a 4 1/2 d stamp was money well spent. Here is a link to 29 Palatine Road, Goring by Sea, Sussex in Google maps in case you wanted to know where your money went.
The Old Badger must be rolling in it. I never joined the young Badger's Stamp Club, as run by the Old Badger, but I heard it was rollicking good fun. Most important of course was parental approval in those days. Please note the lack of overwrought, fine print legal documents to receive that consent. Sadly I could find no current information concerning Badgers House in Lancing, Sussex.