The Society of Ancients has a sale on its pre-2011 back issue Slingshots on at the moment. You can get a year's supply for the cost of one magazine + shipping.
You can find more info about Operation Balearic here. John Graham-Leigh has done a great summary of the article highlights for each year, and you can find this at the link just given.
There's some good stuff, and this is probably the last chance to get these issues.