"Staves" is the correct pluralization, and always has been. "Staffs" is a recently created word which only applies to "staff" as in "School staff" or "Medical staff" - the group of people, not the physical object.
I've always felt it was spelt with -ves. By the way isn't "staff" in that context supposed to be singular and never plural ?
There are some things even the stars cannot tell me. • TroisNyxÉtienne