Lizard,
if noone gives you a sensible answer can I send you to my two potter friends?
Say Annie the Pedlar sent you (or they'll be confused). Jack is just getting to grips with this computering thing so if he doesn't answer your email try writing or phoning (he is quite old).
OK.... so go to www.tudormarket.co.uk and click on Annotspots tent and talk to her, and or Jacke Green(e)'s tent to talk to him, and there is also Jim the Pot at Trinity Potterys whom I don't know but his wife Emma knows me. He's got a tent on there too.
They are all experts and very approachable and will talk clay till the cows come home.
AnnieAnna