1950s Black Suede Metal Heel Spring-o-lator Heels

The heels are in near mint condition, missing some jewel detail, otherwise mint. Black suede with metal heels. Jewels are on the front one is missing from one side and jewels on the back heels, both are also missing. Springs of spring-o-lators still in tact and full spring to them. Made by Ferncraft for La Rose. Marked a size 3 1/2 M and measures 21 cm insole, 9.5 cm heel, 7 cm wide across bottom.