Godan's a high grade, and I wouldn't imagine a koryu art is easy to advance in.
Muso Jikiden Eishin-ryu
Systems: iaijutsu (odachi); also training in iai-derived paired exercises ("kenjutsu")
Date founded: late Muromachi period (ca. 1590)
Founded by: Hayashizaki Jinsuke Shigenobu, ca. 1542-1621
Present representative/headmaster: There are several lines of transmission, the senior representatives of which claim to be the headmaster or the most senior authority. It is difficult, if not impossible to determine which of these are valid claims.
Primarily located in: throughout Japan, with many dojo located in the Kansai area