Kirkuk, its oil and its politics will be subject in news for years to come. For demographics check
http://en.wikipedia.org/wiki/Kirkuk
As for the crescent and star, if we take it as ottoman symbol we talk for the period after 1910, that is fine with my estimation of jambiya. Turkoman? I cannot say. But also the kurdish origin is possible. Kurds in early XX century had periods of revolt and periods that served the ottoman rulers.
The two knifes are similar in decoration but different in form. The first has more kurdish hilt and the second more iraqi.