pederson/johanson

I am trying to find Norwegian relatives, we lost contact in the early 50s,my greatgrandfather was Hans peder Pederson, he was born in Fredrikshald but moved to Onso, my grandfather olaf Pederson was the one who came to Scotland in 1888, he was 31 then, he lived in Glasgow. Our contact in the fities was a john johansen he was adopted apparently by the pedersons and regularly wrote to us we lost touch after my father died, my father was peter Petersen.