守 Kami
大掾 Daijô
掾 Jô
介 Suke
1. Kami - Kami means Lord and would be seen in a mei that may read for example, Iga (no) Kami in your case would mean Lord of Iga province. Hawley’s lists Kami as the highest rank or title that a smith may possess.
2. Daijô - Daijô refers to a Second or Assistant Lord. Hawley’s lists Daijô as the Second highest rank or title that a smith may possess.
Other titles are Jô and Suke. These are pretty much the same as far as rank goes and would rank as Third Lord or Second Assistant Lord.
In the mid 16th century, it became common practice to add official and honorary titles to mei. These were usually in the form of Kami, Daijo and Suke for official titles and Fujiwara, Minamoto, Taira and others for honorary titles. These titles were sometimes handed out by Daimyo and other lords for services rendered, but it is also believed they were sometimes purchased, or given out as bribes. There is some conjecture as to their significance, some say they have varying degrees of importance, others think they aren't all that meaningfull.
--- The above came from the excellent Kanji Pages by Richard Turner: http://www.jssus.org/nkp/common_kanji.html