I've been using the Avent Manual Pump for my newborn and it's been great. Recently I've misplaced the silicone massage cushion and was wondering if anyone knows where I can buy this separately without needing to buy the whole manual pump set? Avent does have a Comfort Breast Shell package that you can buy but I don't think the "backing cushion" in the package is the same as the massage cushion that I'm looking for, am I correct?