As promised, finally getting around to addressing a couple of points raised earlier:
I offer this bit of supporting evidence for the production period of these Skarnik and Fiszbein eagles. Pictured below is an original, unaltered and complete wz.35 infantry officer’s rogatywka cap from my collection. It was obtained from the family of the officer. It is dated on the inside of the sweatband May 2, 1938 (a known practice of this particular hat maker, J. Miron, Wilno). The original eagle is a Skarnick and Fiszbein product of the same pattern as yours, bearing the familiar anchor mark. This distinct eagle pattern (curiously also produced by GUZPOL) is commonly found on wz.35 officer rogatywka caps of the latter 1930’s. They are not found as original equipment on earlier pattern rogatywki, which came equipped with earlier type wz.19 eagle badges.