I'm doing another 1891 Argentine Mauser stock extension, to make another bubba-ized rifle into a carbine w/full-length stock; this time I milled a 1/2" wide x 3/8" high x 6" long slot in the combined bubba-ized stock & extension...Then I milled a same size Walnut 'plug' and glued it in place...I rough sanded it down...
It looks like a butt-splice, but it's actually a hidden tongue & groove splice.
When I first started, both the stock and extension looked the same color...(I had seven Mauser/Steyr/Enfield stocks to choose the extension from)...I chose an Enfield No 4 stock for the extension...The color looked close...
After sanding, the colors no longer match...
No matter.
The barrel cap, front sight band & blade, and rear band/sling swivel are en route.