No such formal list of immigrants that came to New Sweden exists. However, I do have a rather extensive data base with information on thousands of Swedish emigrants that came to New Sweden, Maine and the surrounding communities. There is also a partial list of immigrants that was compiled in 1929 by Marie Malmquist titled Läpptäcke that is included in the Maine's Swedish Colony Centennial History from 1970. I checked my data base and I don't have either Per or Oskar listed. I found them on the Swedish emigration data base known as emibas. They emigrated on April 5, 1871 from Södra Sättra, Svennevad, Örebro (Närke) to "Nordamerika". I checked the Malmquist list and they are not included on that list either. But as I said before that list is incomplete.
Are you sure they were heading for New Sweden, Maine? If you have additional information to share with me I would be happy to help you try and locate them.
The only information I currently have is that which I found on emibas:
PER ADOLF EKMAN born 10 Dec 1826 in Bo, Örebro
HILDAADELINA EKMAN (his daughter) born 31 July 1856 in Sköllersta, Örebro
ADOLF OSKAR EKMAN (his son) born 11 Nov 1859 in Sköllersta, Örebro
Their emigration date is noted above.
Two years later on 15 Aug 1873 three women also emigrated from Sweden. These women may have been the wife and daughters of Per (as they came from the same parish and the birth dates of all of them appear to be logical, they are:
CHARLOTTA ANDERSDOTTER born 19 June 1829 in Bo, Örebro
ELIN CHARLOTTA EUFENNIA born 15 July 1869 in Svennevad, Örebro
ADOLFINA WILHELMINA born 23 August 1852 in Sköllersta, Örebro
Let me know if you'd like me to look some more. I do have several Ekmans in New Sweden, just not yours, maybe some of the Ekmans that I do have are family members of yours.
Chairperson New Sweden Historical Society Genealogy Division