Canadian Lee-Enfield sling assembled 1943 by Savage. (http://www.rollanet.org/~stacyw/british_slings_overview_page.htm)
Steel was a wartime replacement for brass.
As to it being an RCAF sling because of the tan colour, so far as I can tell, the Canadian Army 37 pattern webbing was all tan, with a shift being made to green c. 1951. The 37 pattern could of course be blanco'd, but tan was the normal colour.
Ah yesss, Blanco. The mills equipment company's brochure stated the sling could be easily cleaned with soapy water and a brush. THEN some TWIT invented Blanco.
Going back in history, troops were issued with two clay pipes. One for smoking and the other to be ground up to whiten the leather equipment.
Gotta love the mindset that leads to such.
One bit of historical trivia. The night preceding the battle of Waterloo was a very wet one and the troops of the day of course had no tents. Most of their white leather accoutrements were by first light stained red by dye washing out of their scarlet tunics. By coincidence, when a 150th anniversary recreation was done, exactly the same thing happened.
Add the fact that the battle started late because the wet ground prevented the little corporal from properly emplacing his artillery untill much later. Still, it was in doubt until Blucher showed up.
This sling is beige P37 on my screen...![]()



























