I'd re-shape what's there. Find some photo's of good looking stocks that would fit inside the profile of the Baikal. Since the rifle has a splinter forend, a straight grip will give better hand-eye co-ordination - more like a fine (and properly designed double) shotgun.

The one I saw localy had promise fro design changes. If I owned it, re-modeling would be the very first thing I did - even before shooting it - well, before shooting it much past testing.

Adding wood in never a good idea - it is too obvious when done correctly, and ugly to most eyes. The stocks as they are delivered are very generous, ie: oversized and can be trimmed, changed and slimmed easily.