Managed to get the theme pretty quickly but had to check a few of the themed solutions as I'm not a crockery expert. I have finally finished but am unable to parse14a, despite spending ages looking at, which is bugging me rather.
Thanks for the hints on 21d and 25d. They made me realise I had the wrong answer for 24a, CAMBER, which fits both 'slope' and the definition, but not the down answers.