1. Stuff needed: piece of leather, a wooden liner (made with the puukko in question), an awl, the puukko itself, glue, a couple of sturdy needles, thick thread (this one is waxed thread). Also needed were pliers (LM), leather wax, a sharp knife and a rivet.
2. Unfortunately I didnt have a camera while I made the liner, but its a pretty simple task: I just took a piece of pine wood, attached it to a vise, and carved away. A belt sander helped shape the outside. This liner is for right handed sheath.
3. I wrapped the puukko in plastic, taped it lightly, fit it in the liner, and measured and soaked the leather. The leather needs to go at least over the thickest part of the handle, but I like to make a more deep carry sheath. There are a lot of different views on how wet the leather should be. IMHO it's not that important, as long as it's wet enough to shape well 'round the puukko.
4. I measured and cut the thread (app. 5 x the lenght of the sheath) and put needles on both ends. Then I just started stiching. Heres the beginning: started from the top, went down a few stiches, back up making a "D" -shape, and then back down again through the same stiches. Here's where the LM came in handy; pulling the needle through was a little difficult. Since the leather was really thick, I decided to tie a knot on every stich like shown here.
5. Finally, at the end. While stiching, one needs to make sure the leather is tight, and I mean tight. A good rule of thumb is; if your right hand thumb isnt hurting at half way, your doing it wrong. Once I reached the end, I stiched back up a few stiches, and tied a double knot like shown in the previous pic. I then cut the remaining thread off.
I put some glue inside the seam, and cut off the extra leather with a knife (if you ever decide to make a sheath like this, this is where you need to be extra carefull. At this point its real easy to slip your knife and ruin the sheath. Or your fingers. Or both.
6. While the sheath was still wet, I made some decorations. I used a stainless steel high tech leather decorating device (aka. a "spoon")
After this I let the sheath dry overnight with the puukko in it (this is why the puukko is wrapped in plastic: otherwise it would rust).
After the sheath was dried up, I could have dyed it, but I decided just to wax it (I kinda like it more that way, since it shows patina better)
7. The belt loop is made from the same piece of leather. I drilled a hole to the "D" shaped circle (a SAK Farmer awl is great for this), and added an odd 8 shape ring to it (found these from our local hardware store. For example a D shaped ring would have worked just as fine). I attached the leather strap to the ring with a rivet.
8. And here it is. Not the prettiest sheath out there, but does the trick.