Thanks, Ivo, I'm familiar with the recent Chinese ones (there was one on the shelf in the shop alongside this one today - I don't like them) but this one doesn't seem Chinese. The ridges remind me of some Stoelzle patterns, but I had a niggle that someone else here had asked about one like it recently and I can't find the query... it has some age, and was absolutely filthy when I found it - looked like it'd been stored in a shed or cellar for eons!