I found this weird dovetail joint in a 1960 edition of Mechanix Illustrated (Vol.56(7), July, pp.116-117). It almost looks like an impossible joint, but with a little bending, and some ingenuity, it is possible. The angle of the dovetail is 15°, and the joint requires removing a good portion of the cavity in the pin-board. This allows it to be bent so that the tails-board can be slipped into place. The small piece of wood that was removed is replaced during assembly. An interesting joint, but likely not at all practical!
working by hand 