"Guess-the-Name-of-the-Jeweller-Contest" - Hint #4

I think I have a winner. But since I promised 4 hints, I am publishing the fourth and last set of clues now, to give me some time while I prepare my post to announce the winner(s) and tell the whole story later on today.

****Please leave a comment if you think you know the answer. I've decided to offer runners-up-prizes.****

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Hint # 4 - Together with his staff, his jewellery company made a unique art object for an important holiday, once each year, starting with 1885 until years later when his company was forced to close. In making these jewellery-objects, he often incorporated ingenious mechanical mechanismens because the object was to have an element of surprise. It took a year to make each object, during which time all information about the object was a well-gaurded secret. Thanks to his ideas and the good working conditions he had, his company's products reached a pinacle of craftsmanship, impossible to ever attain again, because, among other reasons, his technical notes have vanished.

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I'll get back with you later today, Wednesday March 31st.
In the mean time,
be happy!
Anna