Replacement window flange, Pella Proline double hung bottom strip

I have a house full of Pella Proline double hung windows circa 1997 that need replacement weather stripping/bottom water flanges inset in a groove in the bottom of the bottom window pane. The attached photos show a removed strip that is probably slightly stretched from being pulled out of the groove, but should give a good enough approximation of dimensions. Can you source this? I have about 25 windows of about 36 inches wide (have to do a complete inventory with dimensions, still.)