I had just unpacked it and was looking forward to take apart this little gem, when an EMail arrived from Finland.
Janne, the owner, casually mentions that he operates an 8 ton magnet at work. Could it be magnetized?
I quickly open it up, and the hairspring sticks in that peculiar fashion. On to the demagnetizer, and the problem is fixed. The movement looks very clean, and it does well on the timegrapher.
Back to Finland free of charge – and I would have liked to take it apart so much!