I am looking for an ancestor my grandfather’s brother Harry Roslund born 11 June 1903 in Sweden. He left Sweden at 17 and sailed on several boats in Europe before left for US. He came to through Ellis Island and settled in Mobil AL. as a sailor.

I have tried to find out what ships he was on. I also got a social security paper that I ordered from US. That is how I now he lived in Mobil AL. and worked for the Waterman SS Corporation. I think he served on a merchant ship during WW2. That is where the trail stops.
He passed away June 1976 in New Orleans and lived around Louisiana Superdrome that is where he picked up his pension.
I believe he worked for Waterman the whole time because the Waterman SS Co. is located in that same area.
It is a long shot, I know but when you live in Sweden it is hard to find clues.
I don’t now anything after 1950. Any lead is of interest.

Where do I turn and who do I ask?

These are the different names he uses:
Tage Harry Roslund
Harry C Roslund
Harry Tage Roslund

Can any body please help me?
Best regards
Per Roslund