Hello!
Resurrecting this old thread as it seems the right place to note an interesting article on the subject of "Tamgas and Runes, Magic Numbers and Magic Symbols" by Helmut Nickel, Curator of Arms and Armor at the Metropolitan Museum of Art. You can
download a PDF of the article here
There are many figures included and these may help in identification, interpretation and other study.
Best Regards,
Dave A.