PS
I have been trying to get a close up look at the buckle on the sling pictured on the 1/95th forum and it just does not seem to show that fine of detail. However, their sling appears to be an early or maybe the original style sling.
The manner of attaching the rear loop seems the same as the Brown Bess Musket of that time period and earlier periods. IOW, 4 holes with a leather lace through it and tied.
I agree with some of the posters on the one link that normally in this time period, the buckle tongue should be Iron and not Brass, though it is possible they were made of brass.
I’m not sure if the extra leather loop/slide on the front part of the sling is correct, but it may be. Brown Bess slings did not normally have this extra loop/slide, but many of us who reenact with the Bess add a loop/slide like this to help ensure the buckle’s tongue does not come out of the holes in the sling leather.
Gus