Another option would be to export as .obj from Nifskope then import to blender -- export from blender to .obj and then reimport to Nifskope as .obj
Ah, thank-you, that seems to have worked for me

I still have a few issues, but I think that is just me not being good with Blender

Edit: One last thing, is it possible to load texture date in Blender? I never used it too much, so cannot remember if it is possible... :/ It would make things a little easier, I think, if I could see which bits I am meant to be changing...