Wladyslaw Leszezyszyn family search in Poland 1. Open

My great-grandfather, Wladyslaw Leszezyszyn, is Polish and we didn’t know it. We only found out about it a couple of days ago while cleaning my grandma’s house. His dad’s name was Pietro or Petro and his mum’s name was Olyanna or Julyanna, we didn’t understand the handwriting well. My great-grandfather was born between 1908-1910 and he emigrated to Argentina in 1929, and he lived here until he died. Any information would be useful, thank you!