I was doing Guardian crosswords 25 and many more years ago, but this one does not ring any bells. I was amused, though, to recognise Paul's style with my first solution: 8 across. I agree there are several very clever clues and I specially liked 10A.
Although I finished it, one or two I couldn't parse until I looked at the Forum, so thanks. In particular, I had never come across Finland's original name, so I needed that explanation.