I looked at Runes in Farley’s book. It appears there were two forms. One of Old Norse (Futhark of 24 runes with likely dates in the US of 600 to 900 AD). the other the Scandinavian Futhork of 16 runes called the Younger Futhork and used in the time of Phillip. There is a lot of material in her book on the runic inscriptions.
I'm going to do a net search to find OTHER STONES that could be benchmarks located at roughly 1 degree intervals East and West, and maybe North and South.
All I have to do is FIND ONE and the die is cast ~ book time!