Eric,
I have no idea but many builders/collectors viewed it in detail at the Front Royal show and no one suggested a re-stock, doesn't mean it isn't but it seems more like some really good craftsman made it for target shooting. If it was a re-stock surely the lock/barrel would have some type of id. It does not have the most appealing lines but it seems well designed for target shooting, at least for my hands.
Ed Rayl looked at it and said he wondered if it had a French connection. He said that someone told him (and he could not vouch for it) that France did not require that firearms, exported to other countries, have proof marks. He said he had also seen some French barrels with similiar rifling.
When I did a Google search on "Yelin" surname it looks to be Jewish.
Whomever made it certainly knew what he was doing, its a very well made gun.
Dennis