Sorry but except for repros most if not all of the ones I have ever seen have had rifles attached. And being leather, they tended to deteriorate. You are looking for a relatively rare accessory and the only thing I can think of is some kind of gun collectors websites, posting in WTB or looking For Sale, or the gun auction websites. They gotta be out there because alot of the vet bringbacks were sporterised early on before the guns became collectable valuables. But that leaves alot of time for them to lie aroud and get lost or rot or get tossed. All I can say is keep googling from time to time. And your search might be outside the US, too as a good place to look might be with sellers in Britain and Europe. Actually I can see a situation where they might be easier to find there. And a sling should present no customs issues. And, beware fakes. Or repros sold as original, or slings made for like, Israel, or Yugoslavia, etc. that were practically identical, except for the markings. Those could fill in and look OK for now.