The Wahkon Bay finish is okay, it works. I used it on one project a few years ago, was easy enough to use. Just about any finish is gonna have trouble with water if your foolish enough to stand out in the rain, wood swells, as for wear and tear it's not bad. Personally I don't think it's any better or worse then other stuff out there. I just don't think you get much in those little bottles for what you pay. As for your inlay, you can make a new one that is slightly larger and thicker to go over the area inletted too deeply. Or you could acraglas gel it (slightly thicker) so it sits where you want it, but you better get it right cause you ain't gonna pull it back off afterwards. I'm not a stickler about using the stuff for little repairs, but if you have major goofs it will show in the finished project. One thing that I've learned is that I tend to leave too much wood on a rifle, are you sure that you can't bring the wood down to the inlay without distorting the shape of the area?
PS. I didn't see that you were working with a walnut stock. The Wahkon Bay stuff will work but you might what to do some searchs on finishes especially if you want to fill the pores. Depends on what you are looking for on a finish, filled pores is a whole different animal.
