In Central Javanese keris belief of the1980's -'90's Pajajaran I was a a West Javanese (Sunda) kingdom that existed approximately concurrent with Majapahit.
That kingdom gave its name to a West Jawa era, and then a keris tangguh classification of Pajajaran I, Pajajaran II & Pajajaran III.
Somebody who absolutely believes that the tangguh belief system indicates a time period will also believe that a keris blade classifiable as "Pajajaran" dates from the era of historic Pajajaran.
This is what I was taught, and in the presence of my teachers and other True Believers, I also believed this, and in the presence of any True Believers today I am quite prepared to believe the same thing:- at home, in my village, I believe the same things my grandfather believes. Never argue with Granpa.
However, realistically these very old tangguh classifications are stylistically based, and a keris blade of that style will in most cases originate in the geographic area related to the name of the ancient historic political entity.
https://en.wikipedia.org/wiki/Pakuan_Pajajaran