I'm hoping this might catch the eye of a Finlander in the group.
I have an old booklet printed in Finland at the turn of the century (the previous one, that is, around 1900) titled "Metallityon: Opas Maalaisille" by Tieto Ja Taito. It has a picture of a lock and two keys on the cover:
I'd send a digital copy of the complete booklet to someone who wanted to help me figure it out. It was from my Finnish stepfather's estate, and was his father's who I know nothing about. thanks,
Ken Grunke