Although the original release of Hammer Horror comes in a thicker card picture sleeve, it's not nearly as thick as some of the other earlier sleeves. Despite that, when you compare it to the reissue sleeve, which is cheap paper, there is still a considerable difference between the two.
The back of the sleeve has rounded edges on the folds, and the opening is a long rectangular shape with angled cuts at the sides.
The typeset and positioning of text differ on both the first issue and the reissue. Also, first issue releases have the inscription "We're All Playing A Hunch!" etched into the run off vinyl on Side A. Reissues do not have this inscription.