About the propeller. The propeller was produced almost for sure by Polish workshops Szomański Warsaw, however completely tarnished marking precludes  full identification. Propeller suffered ground contact.  Privately owned (Dęblin 2020).

Construction.  The propeller lamination consists of 5 plus (1 narrow), ash plies. Propeller coating was black, most likely Tonkilaque.

Aircraft and Engine. The propeller was used most likely for RWD-8 (which can be confirmed by diameter) or RWD-13 The propeller was working with 4-cylinder in-line Gipsy Major engine  (PZ inż. Major 4), that can be proved by comparison of attached hub. Engine cubic capacity – approx. 4 litres.

References:

1.  Opis Płatowca RWD-8, Ministerstwo Spraw Wojskowych, Departament Aeronautyki, Warszawa 1935