Hi,I can add just a little I think.They arrived in NY on Feb 15, 1921 on the STOCKHOLM which departed from Gothenburg, Sweden.Your Great grandfather was a butcher and your great grandmother was a housewife.The both spoke English as well as Swedish.Your Grandfather was about 2 when he arrive.You Great grandfather was about 26 when he arrived and your Great grandmother was about 28.
I'm going to guess on the S for Charles' middle initial.It could be Sven (Swain in American English).
Lars Johan Holm resided at Brunskullen 6 (or 8) Hallsberg, Sweden.
If you want to find more information, I could provide you with a Geneologist in Sweden that may be able to help you.There is a charge for her time though.Send me a private message to email@example.com
There is a picture of the STOCKHOLM on the Ellis Island site if you haven't been there already.
Do you know whether Lars Holm came to the US in 1900?If so, he was single at the time, 23 years old...arrived on the ETRURIA which sailed from Liverpool on April 28, 1900 and arrived May 6, 1900. He was possibly headed to Pittsburg upon arrival. Looks like he was going to live with a friend...something that looks like L Westling but all run together.Hard to read. He was a laborer.
Hope this was a bit of information you didn't have.