Used to see a lot of those Rosengrens pressed steel keys, but the ones we saw always fitted the cylinder locks. Have never see those keys applied to a lever lock style like your one before- perhaps they are rarer…It looks to be much later manufacture to me though. Here’s one of the types we used to see, think they applied them widely to cover many applications.
Up until a year or so ago, I had a box of original factory blanks for these.
