Some thoughts (and nit-picks):
1. Some of the guns lack information about moving, and rules for giving the crew cover. Most notably the Bofors AT gun, but also the Madsen automatic and the marianne. I don't know about the others, but the Bofors had a gun shield, and the others could use some rules for moving. (I know they are the same, but when you write them out on each and every gun and then "forget" them on a couple the players are going to wonder...)
2. No Snipers? IIRC the finns did use snipers, or at least sharpshooters of some kind.
3. In the command squad the Lieutenant has an SMG, but his sergeant can get a M31/suomi. (I take it that the lieutenant should have M31 too.)
4. Since the list is for the winter war, some rules for snow could be fun. And then the list should have ski troops -- which really are ordinary troops equipped with skis. Would be a good way to differentiate the finns from russians, to be able to give all finnish units skis.