Z3 belongs to the later company. Its initial fleet came from Polska Zegluga Morska and probably retained that livery at first; Janes 1987 supplies no separate funnel.
A later company of the same name, also called Polish Shipping Co., was formed in 1982 under Polska Zegluga Morska. Its fleet was managed partly by the parent and later through Polsteam Oceantramp, Shorttramp and Tankers, held jointly with the parent.
Poland, Szczecin.
Keep the explicit scope label independent; no alias or company identity is inferred.