Please apologize for my late reply.
First, I do not know much about the steel used, from what I've read, it's a self made one containing 13% of chrome and has 54/56 HRC.
For the rest, those knives are stronger than they could look. They do have a razor edge as soon as you buy them, and they keep it longtime but it's a pleasure to sharp them if you have to. It resist well against salt or acid (no problem to slice any vegetable like tomatoes)
Most of the time the handle is from different wood made (and the type of the wood determine the price).
The one I've bought has a rubber/lether handle, it stay well in the hand, even when wet or oiled (really important when blood goes on it).
If you buy one analyze it well, the blade must be wonderful and signed "Marttiini". Say this coz'one knife seller has try to convince me that the knife he was showing me was one Marttiini but if the sheath was signed the blade wasn't and looked like an oyster opener you can find in supermarket.
The sheath is a "double" one, inside you have a kind of "Kydex" one wich maintain well the knife in, over it you find the sheath self
lether or cordura (as the one I bought).
Hope this give some info
Others good puukko makers are
"Rosseli"
http://www.roselli.fi/
"Lisakki"
http://www.iisakkijarvenpaa.fi/