kogatana with serrations

I found a site showing kogatana collections.

http://www.geocities.jp/ntooma/kogatasya.html

The first one which was made by Kuniteru (国輝) has a saw on its mune. It reminds me of a Kaifuto (海部刀) with a saw which was introduced by Guido before.

Judging by how close the top kanji is to the serrations, I would expect that the serrations were added on later, after the blade was signed?

What age is this kogatana according to the site?

The style of those serrations is very advanced, and is the type seen on modern knives with the offset teeth, and would have been extremely effective. I am curious to know more about it, and the age estimate, as I would be suprised if there can be all that much age to the serrations?

Brian

The explanation for the kogatana is loosely as follows;

Mei: Ise no kami Kuniteru (伊勢守国輝)

mid Edo period, sword smith in Osaka.

This kogatana is especially thick at its mune to have serrations. Although the turnover of boshi of ordinary kogatana is generally long, it of this kogatana is short to make it possible to set a saw.

According to my books, this Kuniteru seems to be a smith in ca. 1670.