In case you're still interested I did find some information about Anders Johan Jonasson. According to a tree on Ancestry.com here is his name and what he changed it to:
08 April 1838
Mistelas Parish , Rydaholm, Jonkoping, Sweden
Born Anders Johan Jonasson Hägg (Hägg being a soldier's name)
Change it to Paul Munson when he emigrated.
He died 13 Jul 1906 in Ellsworth, Ellsworth, Kansas. In several trees there is a variance in the birth date - 8 Apr 1843. Now I would normally be suspicious but my grandfather was born in 1860 but varied his birth year by 5-10 years on various records so it can happen. You can find Paul Munson's memorial on findagrave.com. Perhaps some of this will lead you to finding sources and family information here in the US. You could go to on-line repositories to do your own research to find sources to prove that Paul Munson actually IS your guy. Best of luck.