I believe an NSKOV police bayonet model existed however they are a rare item. There have been a few over the years and all I’ve seen (except one) had issues making it likely they were postwar embellished.

On this one, why would the NSKOV use a Weimar cut-down police bayonet which was an issued piece? If the NSKOV ordered one or several, they would likely have been private purchase items without issue marks.

This was probably a standard police bayonet that someone denazified by removing the original emblem and some enterprising individual replaced it with an NSKOV stickpin.