I was just looking at Peter Abbott's book and wondered if it might be L. clarki? I recorded some amabilis a month or so ago and this seemed slightly bigger (though I don't think estimating size is my strong point!).
Yes it could be L. clarki. Unfortunately the feature that distinguishes clarki from amabilis is the shape of the plate at the end of the abdomen, which we can't see. Size can be helpful, but as it varies within species, it has to be treated with caution.