I'm really surprised you've had a sub-par experience from Graham Taylor at Potted History - he's always been quick to respond when I've contacted him and as you say his work is of very high quality & he researches and uses authentic methods and materials. Being local, he's used widely here in the north east. I've really enjoyed several heritage skills courses he has delivered too.
I'd certainly recommend him as a supplier for any period clay replicas and for demo and skills training work. As an independent craft business he relies on his reputation, so I'm sure he'd want to resolve any issues you are having, so it might be worth giving him a ring if emails aren't working - his number is on his
website and he's active on twitter too so you could try private messaging him there.
Hope that's helpful,
Yvonne
