For the proper red/orange original recoil pad search "original S. W. Silver recoil pad".
Doing a quick look I see that are available in the USA via Galazans and Midway, or in the UK by Kynoch.
Doubtless available in Australia as well.

Do have a careful gunsmith/craftsman do the install on this fine old rifle.
The originals were usually lightly "varnished" after installation on the rifle in order to keep the pad looking better.
- Mike

EDIT: .......ah, I see Rockdoc/Chris just beat me to the mention of the Silver's pad.