Gentlemen, question regarding Hamilton 917 and 921

[A.F.W.]

Gentlemen:
Are the balance wheel and staff on 917 and 921 interchangeable ?
Thanks.

[Samantha]

I hope that this is open for the ladies to answer as well, even though it is addressed to the gentlemen ;) According to my C.&E. Marshall Handy Manual, they take the same staff, Factory #607100. The 923 and 945 also take this staff.
Samantha:)

[A.F.W.]

I hope that this is open for the ladies to answer as well, even though it is addressed to the gentlemen ;) According to my C.&E. Marshall Handy Manual, they take the same staff, Factory #607100. The 923 and 945 also take this staff.
Samantha:)
I am sorry Samantha. Just assumed that most of the readers were men.
Thanks for your reply:)