it's an old machine gun sling. needed to be slightly modified. a few tips from a great leather expert here helped out a lot. the sling is very flexible, probably due to the age of the thing (? i'm not a leather expert). i think the color and aged look fits perfect.
i´m really jealous! what´s the name of the store you bought it? any chance that the guy manages to get another one? whree do you live ? i´m from stuttgart.