Regarding the signatue initials: It appears to be E not a G.
As for the second initial a N fits, note the descender from the y in truly is crossed and nt part of the initial.

In which case this could be from Ellis Johnson b 1830 North Carolina, d 18 Dec 1899 IT, married to Lucy Mik a Lalk and living in Tahlequah during the war.

John R.