Do you happened to have a scan or a picture of Elias' death certificate. I would like to take a look at the spelling of it.
Was the "Ogla Aloa Mattonen" a typo? That would be "Olga", right? Also, "Aloa" is not a real name (nor has it ever been given to a Finn). Maybe "Alma"?
You mentioned Heikki Perälä was born in Ullu. Did you mean Oulu?
This info might help search for them.