321 register handset sizes question when ordering replacement handset

I have a project CH27 C12 that I’m tinkering with and have been scouring the internet for black subdial hands for months. No luck of course but I see the white 321 861 hands available on a regular basis. My question is if anyone knows the mm size of the hour minute and seconds hand because this has been difficult to find. It’s just a fun project and I am using spare parts to create a running wearable piece. Regards -Scott.