The only other information I have is that when he was living in Poland he was a lawyer.
I think that maybe some information is mixed up here.
It appears there are two people with that name and both served in WW2, and coincidentally both were also born in the same place.
Lt Col Stanislaw Slesicki celebrated his 100th birthday in January of 2013. He did have a brother who was killed in Poland and also worked as a lawyer.
Stanisław Piotr Ślesicki was born on January 18, 1913 in Cierpigorz, in the district of Ciechanów, as the eldest child of five children of Tomasz and Genowefa (nee Jabłonowska). In 1920 his parents moved to Chełmża, where Stanislaw graduated the State Humanities High School.
In the autumn of 1931 he began his studies at the Faculty of Law of the University of Warsaw. He lived then at his cousin Henryk Ślesicki - assistant judge. In 1935 he graduated and received a master's degree in law. In 1936 he was appointed to serve a one-year military service in the 20th Infantry Division (...)
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If you type the name into Google, the Polish results are talking about this person. If you click on English results only, it comes up with the person you are interested in.