I've got myself a Joseph Rodgers and sons which I've had a go at restoring the blade on.

Got rid of all the rust, which fortunately was only surface rust and there was no pitting. Sanded it back with a progression from 100 grit through to 2000 grit and I am happy with the results.

however there is a reasonable amount of patina that I wasn't able to remove on the upper part of the blade.

I'm not that worried because my experience with CS knives is that patina is harmless on knives, but should I go back and re-sand the blade to remove all the patina?