Ok! I agree with you!
The thing with viking or anglo saxon style was not my intesion, it was the centuries. In the book they often make no clear cuts, so you can find a viking / saxon sheath beneath a 14ct sheat, and i find it is not useful, because there are many people who not studied archeology who read this book. And I´ve seen Vikings with wrong sheats on reenactments and talked to them and they sayd: "Hey, its from the York finds"...
My thing is to make clear, authentic repros of leather finds for reenactments or museums. And of course, you can do your sheath as you want as long you don´t say it´s a correct repro.
So long, hope you don´t ge me wrong!