I have an original Jap canvas rifle sling with original quick detachable frog clips on it. It is I would say about normal condition for its age, a bit dirty and stained but sound.

I would like to sell it but have no idea if it is worth $40 or $200.... Jap Sling

Password is Japsling

Couldn't quite id your sling from the photos. Here's a link which might be useful in determining what particular type of sling you have.

http://www.rollanet.org/~stacyw/Jap_T99_Sling_thumbnail_version.htm

It is this version with the steel quick detachable clips. They look kind of odd but they work well.