Compare the tuning pins in these two pianos. They are around the same age and both are school pianos. I advised the music teacher that the one on top was very concerning because of the amount of corrosion.
Rust on strings and tuning pins is always a red flag! Having another piano around of similar age and design helped demonstrate the problem in this case. Often piano owners don’t notice rust or corrosion in their piano because it looks “normal” to them or they don’t ever look inside their instrument. Sometimes you can learn a lot just by a quick look!