I thought this might be a post warM1 carbine sling but my books show they have curved metal end caps. Is this a repro, perhaps? No markings. Found in my closet and don’t know where it came from.

 

Any help would be appreciated.

It isn't a US version. I think this was one of the European copies made for use in the 1950s-70s. 

RC

Yes, that makes sense as it has the British-made style buckle, and the metal end caps aren’t the wartime “C” type.

It could be Dutch, is the snap marked?

I’m not seeing a single mark of any kind on the canvas or on any metal part.