weatherstripping for Kolbe and Koble window

This weather strippoing is from 20" octogon shapped solid wood Koble and Kolbe window from approximately 1995.  There is a 1/16 saw cut on the 2" edge of the window that seals against the window fram/sill. Stripping pushes into that cut so only 3/8 seal flap is visible.  Seal flap is nearly flat, but slightly slopes up to create the seal.  Its gotten old and brittle and is disintegrating.  Is there a K&K part for this or some other similar generic part that will work?