Meaning of Kaszubowski
Kaszubowski surname may be connected with the Kashubian region located in the northern Poland - Kaszuby.
You may also check this thread related to people who live in this area: https://polishforums.com/genealogy/descent-something-called-kashoop-kaszub-59035/
Probably misspeled - Grzelak is the common name in Poland.
It should be Grzegorz (most likely another typo of yours)