Another feature is the trim size. The new series is a bit larger than a mass market paperback but smaller than a trade paperback. They have the feel of the well made White Circles.
Also the new series has published in a genre that was very popular in the White Circle series - crime/thriller. Crime and Guilt is a collection of true crime stories. White Circle had a similar collection.
White Circle CD 378 - 1949
White Circle 378 back