The Correct Sling for a New Zealand No.4 Mk. 1 (LB) would be a Khaki sling made by the Canadian's for the their rifles. They come with both Brass and steel fittings. We didn't' have special slings for the rifles, we used what came with them for decades, then used the same slings with the L1A1 rifles, not the nice new ones that were supplied with the L1A1 rifles, they would have to wait to be used when the old .303 slings had been used up. If its a Savage No. 4, Mk. 1, then look for one of their [S] marked slings and use that..... or a Canadian, British
, Australian
, South African, Web Sling.. they system didn't care where it came from, just that it matched the description and was serviceable.