Back then Kahr wasn't using Cerakote as far as I know.
Cerakote was started in 1984, and it was only in fairly recent years that it was commonly used for firearms applications.
I "think" (note the qualifier) that Kahr only began using Cerakote when they started offering colored pistols, which is a fairly recent development for them.
Back in the 90's Kahr steel was chemically blackened.
I "think" (again note the qualifier) that the barrels were in the white, not blackened.