wilkinson sword emipre 7 day edition restore question

right, got hold of one of these bad boys off fleabay. and all is pretty much done and although ive managed to get most of her all cleaned and tidy i came stuck with the blades. now ive obviously taken them out of the holders but i cant get rid of the patina and general black crud on them. is this a case of perseverance with polishing as i really want to save the etching on them. or do others just take it for granted that they have to sacrifice this in order to clean the blade??

im sort of at a loss as i want these to stay as original as possible and in honesty i simply like the way they look.

any help or advice received with gratitude