Here's a new set of Rear Brake Wheel Cylinder Horseshoe Fitting Clips (x4) for the following models from Riley - 

RILEY

Riley 1.5 Saloon  (1958- 65)

(** Not for the Wolseley 1500 **)

You get 4 here so that's enough for both sides.

These fit in the outside of the drum and hold the wheel cylinders in place, you will see them i f you put your head behind the rear wheel.

These can rust away or just get broken when you remove them.