Can anyone recommend a good permanent wave/perm salon in London? (I don't want a digital perm)

I'm finding it difficult to see any reviews on good salons offering permanent waves/perms in London. I know they aren't popular but have decided (after much thought!) I do want to go ahead and have one. I have quite fine hair but have had a perm before which took to my hair. Maybe a salon that does it often rather than a really fancy one would be better? Help appreciated.