Leda buttons were produced by General Plastics as a separate brand from 1958. However, the name Leda was trademarked by Beutron on 20th September 1957. This indicates that General Plastics was owned at least in part by Beutron Australia Ltd by that stage. A report in 1964 stated that (General Plastics) makes Leda buttons … and is being integrated with the Beutron business.” A line of Leda buttons continued to be marketed until at least 1966 (see the example below that has both pre and post decimal prices printed).
1960 ‘Pink pages’ directory, Sydney:
Leda buttons were being made by general Plastics and distributed by Roger Berry.
Leda Buttons Sold Under Other Brandings:
Leda style buttons are found on Embassy (G.J. Coles brand) and Kencrest (David Kennedy brand) cards. See below for comparison: