2 X 4 and some tie wire? Is that a custom that I'am not aware of? Sounds like you may have something there.

Just recieved a Benchrest Thumbhole with a finish at 80%. Either the "drunken beaver" was on brake or they sharpened their dull chain. ::)
It's "always" a crap shoot to see what you'll end up with.
If you're nor prepared to do some work to get the fit and finish you want, PASS!!
They're known as a "gunsmith's stock. Not a drop in by and means.
IMHO, still a good value if you know what to expect.