WCF,
I re-did the stock on my Baikal over and under and had some luck in getting it to fit better than it didd before. Here are the things that bothered me the most about it as received. The stock had WAY too much wood left on it, at the head of the stock, around the trigger guard, and especially in the grip are. The main thing that was wrong with the grip is that it was too long for my hand's reach and they had left it sguared in profile.
I have not handled a side by side Baikal but I would bet that at least some of these traits carry over to your double gun. The first thing I did was to use a highly sharpened pencil to mark around the tangs and trigger guard so as to know how much wood needed to be removed. Next I rounded over the squared grip which helped with the righthand fit some. It still is too open and too long a reach for my trigger finger but I can live with it.
After getting to it fit as well as possible with what was there, I then checkered it, stained the stock, and fitted a removable cheekpiece for use with the scope. It is still just a little far to reach the front trigger comfortably, but it is much better. I have learned to pull the back trigger first as it fits me best, and save the front trigger for follow-up shots, which so far, have not been needed.
You can check out my gun and see the pictures of what I did to it by checking post number 126979, which was posted on 02/13/09. Good luck with your project. I would not try to add wood if you can avoid it. Next best thing is to have a new stock made for it. If you have the wood you should be able to get one rough inletted for around $100.00, plus your wood. Bob H.