I bought the Little Green Sheep organic fitted sheet that is supposed to fit both Snuzpod2 and 3, and it is WAY too big for the Snuzpod2 mattress. I'm now reluctant to order the Snuz branded ones as they are also described as fitting both, so are probably also too big. Has anyone found properly fitting ones? John Lewis has moses basket sheets of 33x76, has anyone tried those maybe?