Should these front brake discs be replaced?

[saladdays]

This is a 2006 Honda Jazz (petrol auto). Should these front brake discs be replaced? The braking surface is 21mm thick, the minimum is 19mm. Are they too rusty? Some of the rust can be scratched off with a fingernail.
The discs are at least 20,000 miles and at least six years old.

Thanks.

[saladdays]

Thanks. I'll replace the discs when the pads need doing.