Yup, looks like the usual suspect on the tang crack for sure. There's a good YT channel with stock repair vids called thecinnabar8442...you could tune in for hints.
You can very carefully spread a crack like that using leverage with a bar with the main stock clamped ( padded!) in the vice.. it's a heart stopper at times when you hear the wood crackle! I prefer to just pin...less stressful!
