Thanks. I'll check out the Facebook group and the website.
Census records indicate that Bronislaw Grazul was naturalized, but records for the court where he would have been naturalized are not available online; the records are at the NJ archives, but I haven't yet pursued that avenue.
I suspect that the immigration record I'm looking for is this one:https://familysearch.org/ark:/61903/1:1:JNBM-QTB
The surname is slightly off, and the destination is way off, but the age, birthplace, and mother's name fit pretty well. The naturalization record could confirm whether this is the right one.