An excellent resource for early puukko type knives,their sheaths and accoutrments is
www.arkeodok.com. They have a fantastic cd with drawings and pictures of archeological finds from the island of Gotland Sweden for sale(cheap). It is remarkable how these early knives and their scabbards resemble modern puukkos. Due to copyright stuff I do not believe I can post any of these directly but a lot of the finds are on their website. I like puukkos too.