That is the mechanism for operating the cleaning needle. Typical Lux. More information on that detail in this thread.
Thank's! Do you have same stove or do some of your friend have the same stove? You have sent these pictures: https://classiccampstoves.com/threads/28144 Here I am asking pictures and measures from the burner cap/head: https://classiccampstoves.com/threads/28332 Would you be able to help with burner cap/head pictures and also get some measures?