Re: Wennersten family of Holland,MI
I can't help with your Wennersten at the moment, but if you found him in the 1910 census, then you should know the year of immigration and his age at that time. It might be helpful, at least eventually, to have his birthdate but an estimated year of birth helps too.
I didn't find him on the Emigrant CD but a young child would be listed without a last name on the Emigrant CD. There are some other databases that maybe he could be found on, but it is really hard to do anything without some details.