I've managed to get hold of a few more from the series. Some of these work really well, and some I'm less certain about--I need to see them in the real world. I'm still unsure of the designer(s), too. (UPDATE: All-seeing Alan Trotter tells me it's Pentagram.)
They have a very mid-century, European look, which is appropriate enough. I especially like The Eye and Despair, while Laughter in the Dark doesn't seem remotely sinister enough, even with the hint of blood.