Thanks Keith,
That's the kind of info I was hoping for, I'll give the Titebond 111 a go and see how it stands up. I'd tried Gorilla glue on a rifle stock a while back, it stuck well, but as you say, the frothing mess that squeezed out took some shifting once it'd set.
The split I've got runs down the centre between the top strap and trigger plate so don't have issues with the glue showing but I'm worried about it opening up again if it's not 100% bonded, there's no checkering on the stock or I'd have probably fixed a dowel through and re cut it to disguise the fix as best as possible so as the owner isn't fussy, it's not a problem. There's another small split on the right hand side but that's been there a long time and hasn't got any worse so that'll be a good spot to repair and see if the glue joint shows.
Cheers
Nick.