Nice one Fenris!
I've always wanted one...or many actually...
There have been a few of these plain-hilted ones discussed over the years, and it seems that some may simply have lost their brass cover and others simply lacked them altogether. Different tribes produced these swords, with varying quality.
As to age, you're generally looking at early-to-mid 19th century I guess. I think production generally stopped after the French conquest.
Here is a compilation I made of all the flyssa discussions on this forum:
http://www.vikingsword.com/vb/showthread.php?t=3935 you'll find lots of info.
Emanuel