Copper sliders

[KLR]

I am trying find out when copper sliders became prevalent.
In contrast to lugs - which all seem to be of copper (except occasional officer's ones) - sliders are invariably made of gilding metal. This is perhaps not surprising as copper was surely a more expensive cpommodity than the GM alloy !?

The evidence for copper sliders in various King's Regt badges appears to be a 2nd WW phenomenon. Mostly in wartime production of the regular bi-metal Pattern 10042/1926. They also appear on the Liverpool Irish Pattern 11390/1939, here longer than other sliders.

I'd be interested therefore to hear what evidence there is from badges of other units.
Thank you
J

[Neibelungen]

Other than the smelting costs of alloying, GM is 95% copper, 5% zinc, so technically cheaper.

GM demand would be primarily for brass cartridge production, so switching non-essential materials over to lower demand materials would make sense in wartime.

PS. most wartime scrap metal drives were propaganda tools as 99% of the metal collected was to low quality to be usefull and re-refining far to inefficient to be worthwhile . eg aluminium pans were useless for aircraft production.

[KLR]

I'm pushing this back to the top because although I appreciate Neibelungen's metalurgical insight, I'd like to know about other dated examples.