Hiya everybody' I am new to this site. I have clocks and watches mainly old ones but this question is about a barograph clock. I just bought a used barograph' it's been well looked after and everything seems to be working. I am having too remove the clock and replace the graph paper. Sounds simple but the knurled screw that holds the clock in place is just turning and turning. It does slack off the clock but it's as if the bolt that goes through the clock is turning continuously. and I cant remove it. Attatched is a photo. The two red dots show the knurled screw that wont undo properly. Any help greatly appreciated. Thankyou. Note I did remove the entire brassworking section to see if the bolt was accessible but it must be enclosed within. Thanks.