Sorry Dennis,
I have NO idea who the builder is, but I do agree upon reflection that the initials should be read W.H.
As pointed out, the positioning of the "periods", and I believe that most are signed in such a manner that the signature, or initials are read "upright" when the rifle is held by the shooter in a "Port Arms" position.
Sure is a lot of good work there...hope it shoots well for you.
Thanks for sharing.