Here is the one I am messing with. I have to turn the screw heads down a bit yet but you can get the general idea. The tang extension will butt up to the buttplate & be cut off there, and the piece cut off will be welded under the existing tang with about 1/2" extension going under the buttplate to retain the end of the tang.
This is a Getz 13/16" straight barrel & it had a flared tang & I made it straight tang & then welded on the extension. It is not replicating a rifle I have seen, I just wanted one with the tang all the way to the buttplate for myself, just something a little different.
In this you can see where the buttplate will go.
It made me a little nervous inletting that long tang, as if you accidently bend it & then bend it back, the dang thing gets longer. When you have a eye (I call it) in the middle of it, you can't have it changing lengths, it HAS to stay the same to the eye & up over the comb or when you go back with it the piece is longer than the inlet & then possibly a gap in the inlet. It is coming along pretty good I think, but tedious at times.
On this one, the front tang bolt is into the triggerplate, the rear tang bolt is a wood screw made to look lik the front tang bolt, & the screw at the tang eye is thru the wrist & threaded into the triggerplatel, so the wood is kinda sandwiched there. I figured if I was going to put a screw down thru the wrist & one up thru the wrist, may as well make them one & thread thru the triggerplate & possibly reinforce that long thin wrist a tad. But after studying it, it may not make any dif. at all.........
Keith