Securing hands on Junghans mantle clock

by David Jackson
(UK)

Hi,

I have recently purchased a Junghans mantle clock but the hands seem to have been secured with Blu-tac by the previous owner. I am familiar with the pin method for securing the minute hand to the shaft, but my clock doesn't seem to have a hole in the shaft to take a pin. It appears to be threaded to take a nut.

Can this be correct and if so where could I obtain such a nut?
Thanks,
David