@LPelo, thanks for the photos!
Could you take a close up photo of that "sticker" on the back of the painting? What does it say?
It's certainly in that style, albeit rather cruder than most of his stuff.
To be honest the quality of the photos isn't good enough to judge that...
I'm not sure if there's a Catalogue Raisonné
I don't know, but this painting doesn't seem to show up on Google.
the Muzeum Narodowy in Warsaw may be able to advise.
People often contact Desa Unicum (the biggest auction house in Poland) to identify and get a price evaluation of a painting:
desa.pl/en/