Local Boy - What is the length on the "What Price Glory" m-1887 sling?

Your picture of the Krag web sling replica kind of reveals the 'original sin' of the design. The Mills end 'hooks' were made too narrow on the original 'Krag' design and caused the strap to curl. (The British got it right on their long serving Mills Web slings).

FWIW - 1917 photo of 12th U. S. Engineers in London with Krags shows them using model 1887 slings of appropriate length for Krag.