Final update on this car:
I have got an e-mail from a person in Lom. He verifies that the car was built by Oddmund Kolden in Lom. Another person from Lom, living in Otta as a teacher, bought the car. His name is Olav N Haugen
Mr Kolden also built cabins on trucks and snowmobiles used in the winter mountains, he was probably an experienced car body professional