Movement holder for 321 vs 861

Hello!

i have just embarked on a journey to restore a 321 movement and while looking into the peripherals, some questions have popped up.

Can i use a 861 movement holder with jewel support pins on a 321? (are the subdial jewels in the same location on 321 vs 861)

Could anyone help out with a part number for the Case clamp screws? Failing to find the number on any of the PDFs on Cousins.

thank you very much and excited to be apart of this community!