Hello and welcome!
This forum is full of interesting informations and great fun at the same time, but first of all full of people with great knowledge. To be honest I don't know much about knives like this, but these links should be helpful for the first time, before someone will answer you more exactly:
http://www.vikingsword.com/ubb/Forum1/HTML/000514.html
http://www.vikingsword.com/ubb/Forum1/HTML/000514.html
http://www.vikingsword.com/ubb/Forum1/HTML/000514.html
Regards!