This brooch for Mother uses a Stokes & Sons AMF button soldered onto a professionally made brooch mount.
A Victorian Military Forces Sweetheart brooch. Button backmarked Chorley, Sydney.
A pair of Canadian uniform buttons made into earrings.
General Plastics double-sided buttons
A GP Product card had these buttons on the same card. Closer inspection showed them to be both sides of the same button. The fact that they were sewn on the card that way shows the double sided design was a deliberate marketing strategy.
The example below show a multitude of shades, and four sizes. On the ‘plain’ side, some are fish-eye and some not. The question remains as to whether they were both from General Plastic, or just the non-fish eye type (as on the card). They probably date from the late 1940s.