From 2018, a question about removing staple rust from old comics leads to the pros and cons (mostly cons) of outright staple replacement:
“Replacement staples will show signs of being unbent and ‘re-bent.’ Also, the indents made by the original staples on the centrefold won’t line-up exactly, potentially exposing the switch.”
“I am also wondering if it would require a particular type staple that is no longer manufactured. Those golden age books were thick and big.”
“You should also be prepared to receive a ‘conserved’ label should you wish to have the book graded again.”
“According to Overstreet:
“‘Any staple can be replaced on books up to Fine, but only vintage staples can be used on books from Very Fine to Near Mint. Mint books must have original staples.'”