Box of 12 DUREX Casein KNITTING NEEDLES (Yes you read that right) Gauge 13

An original unused box of Durex Knitting Needles.
Inside there are 12 pairs in several very bright colours.
Made of casein, a plastic made of milk protein which predates modern plastics.
I've been told these are very warm and comfortable to knit with.
Probably from the 1950s.
I have 3 boxes full in 2 different sizes
- Gauge 10 which is 3.25mm wide and 10" long
- Gauge 13 which is 2.25mm wide and 12" long