One thng to keep in mind when sharpening a puuko; keep the whole flat bevel on the stone. The type of blade grind on a scandinvian knife is the blade flat goes all the way to the edge. It's actually a flat grind from the start of the flat to the edge. There is no secondary angle. It makes sharpening the blade actually easier, because you don't have to guess at the angle. Just laay the blade on the stone, and make sure the flat bevel in back of the edge is flat on the stone, and go.
The scandinavian type of grind gets really wicked sharp, and is a strong edge as well.
On the Finn's and the puuko as a weapon; In the winter war with Russia in 1939, the Finn's defeated the Russiaan army in a very bloody winter fight. The russians had a million casualties, the Finn's 250 thousand. Some finns krept into the soviet camps at night, and slit throats with the puuko's. After one winter, 1939 to spring 1940, the Russians gave up trying to take Finland, and went home.
Don't mess with a Finn who has a rifle and a puuko.