No need for pins IMO..that threaded pin repair is(was) a common way military stocks were repaired. Drill a small guide hole, run the all-thread usually brass rod through the cracked and damaged pieces w/the use of the drill and break it off flush. Then file it off. They didn't use glue. It was a mechanical repair. The Brit SMLE's show lots of this type of repair.
I'd do as others have said and pull the cracked piece open as far as you can. Use acetone or laq thinner to clear it out of oil and any old finish and dirt.
Make sure the edges fit perfectly or as nearly as can be made with the original pieces(s).
This may require a little careful knife or chisel work to the interior of the crack to remove a tiny bit of wood displaced over time not allowing the crack to close all the way.
When it's ready to glue, I'd use epoxy if the fit is less than perfect from the need to remove some wood from inside surfaces.
I'd use TightBondII if the fit is excellent and goes right back together.
Clamp tightly with rubber bands, wood wedges and perhaps small clamps as needed. Pay attention to any displacement of the wood from the pressure of the bands & clamps and adj as needed before it sets.
Some small refinishing of the area will be needed when done but repair will as strong as any w/a pin and w/o showing one.
..I'd then glass bed the frame in the head of the wood when done .
