hi alistair
denmark has a few achilles, mostly on oksbollergen i think, there's some stuff still on the german ranges, but that's all i've found so far, try this site www.hartziel.de
you don't need to travel so far as there's 2 cromwells off brecklesham bay and 5 or 6 valentines in the solway firth, you can dive them if you're qualified.
i started looking at tanks in poland before i realised there's more than enough on our own doorstep only trouble is there all shot up, some not as bad as others, but beggars can't be choosers, i'm planning a trip to sennybridge ranges give me a nod if you'd like to come along.
all the best
eddy