John Gee and Matt Roper have pointed out the existance of the non-biblical Book of Mormon name, Gidgiddoni, in Neo-Assyrian texts, the same Assyria mentioned so many times in the Bible.
As they note, "The simplest explanation is that an Assyrian individual with the name Gidgiddanu was mentioned in the brass plates. This was then the source of the name for this particular military leader several centuries later." They also explain that the a is long, an important fact since Assyrian(Akkadian) long a becomes o in Hebrew. Cuneiform does not have an o sound thus various strategies are used to reproduce it.
What's fascinating about this is that the Assyrians conquered and dispersed the Northern Kingdom of Israel in 722BC. By 600BC, Lehi, a Mannasehite, and Ishmael, an Emphraimite, are living at Jerusalem thus indicating that they and Laban, a fellow Josephite, were descended from northern refugees who fled down to Judea. What's more, Lehi's genealogy was recorded on the brass plates.
Laban's "fathers" kept the record which became the brass plates thus their Josephite geneology and the presence of at least one Assyrian personal name suggests that at least part of what became the brass plates was composed in Northern Israel. The following entry is cut and pasted from The Prosography of the Neo-Assyrian Empire.