Rusty staples concern me a lot, maybe more than tape, as being both unsightly and having huge potential for continued deterioration and damage to the book. I can accept tape in a low grade book much more readily than staple rust, and cannot accept a high grade (VF and above) book with rust.
Exactly. Interestingly enough, rusty staples occur in a humid environment, the same condition that sees the pages stay white. I love White pages and hate rusty staples so I walk a fine line. Good point about about the continued deterioration in the slab.