Wilkowiecki, Simmons - Looking for family

Wondering if anyone can help us. My husband is searching for his Birth parents. He knows that his mom was Alicia Wilkowiecki and was not married, his dad was William Simmons both from Poland. She was 19 in 1965 and adopted my husband to his current family when she was in Alberta Canada. It seems she may have returned to Poland after the adoption.

Any help would be great.
Thank You in advance

There are only 189 Wilkowieckis in Poland, so that narrows it down somewhat. The largest single single cluster (50) is found in and around the Baltic port of Szczecin, and the second biggest is in the Sieradz area (27) of south-central Poland. William Simmons is not a Polish name but may have been someone passing through Poland. The only way to track someone down would be to engage a private detective agency.