Classic Crime – Recommendations?

At the week-end I went to a garden party which had a great second-hand book stall. I managed to pick up a few classic crime books, most of them authors I’ve never heard of. Below is a picture of my haul. Writers are Evelyn Anthony (who I do know), M G Eberhard, Nicolas Freeling, Christianna Brand, Jean Potts, Margaret Carpenter and Edgar Wallace (who I think I should recognise but don’t).

Any recommendations gratefully received.