The logo of Duperite on the back of the key tags may be the key to which company used these. Duperite was actually a company with a subsidiary called Moulded Plastics. Duperite was the former name of a well known Australian brand NYLEX.
Hope this helps, please see link below
Cheers Wayne
http://ianwongresearch.blogspot.com.au/2011/11/duperite-dads-day-1956.html
Hope this helps, please see link below
Cheers Wayne
http://ianwongresearch.blogspot.com.au/2011/11/duperite-dads-day-1956.html