Real Estate / American (former Polish) - real estate inheritance / ownership transfer in Poland [2]

I am apparently a former Polish citizen (I left when I was 2 in the 80's) I am currently fully American Citizen. My grandparents have passed away and left me with inheritance (their apartment) in Poland. I have gone to Polish court and with a help of a lawyer I stood in front of the judge and Identified myself with my U.S. Passport. The court after 6 months of deliberation granted me the ownership of the apartment. I did not know that I had to report to the "Uzent Skarbowy" within 1 month after inheriting the property in order to avoid paying the penalty. Now, in order to pay the penalty I will have to setup some tax identification number called I think NPL. I am willing to do that in order to pay the taxes/penalties.

However, now I would like to sell the property, I have a Polish buyer so we went to Notary official and according to him since I was born in Poland and I will need to obtain Polish Identification Number (like social security number) "PESL". I do not want to obtain PESL I will have no further dealings with Poland beyond this. I don't understand why should I obtain PESL if the Polish court has granted me ownership of the property based on my U.S. Passport and not requiring any Polish Identification. I am not keeping the property nor I am selling it to any foreigners, I am selling it back to Polish individual, to keep the property within Polish hands and ownership.

I also have sister that lives in Poland so could I transfer the ownership to her without the need of creating the PESL?

Any guidance in this matter would be greatly appreciated.