Sorry to disagree but I don't think the definition of "brand new" (as they're labelled) is an open one, and unlike what some might like to think the Sale of Goods Act definitely does apply to eBayers who are commercial sellers !
I emailed the eBay sellers of these items (A to Z) and asked exactly what they came with, e.g. whether all the caliper internals were included (e.g. slide pins, pistons, dust boots etc).
They replied and said the following (their capitalisation, sorry) :
So you only get the pistons, not all the other stuff. So that's very very different from what you get if you order a complete "Cylinder Assembly" from Lexus, which does come with the torque plate (carrier), pistons, dust boots, slide pins etc.