I have recently decided that I would like to carry out my own razor maintenance and decided to go on the hunt for cheap practice razors, and i found a couple I was lucky enough to venture into this shop and also find a Coti.... in total I paid 15Euros for 2 old razors and the Coti!
The Coti is however, well used and has dished in the centre... not too badly but i think enough to compromise anything resembling an edge i am hoping to achieve on this stone.

I scratched the Coti with the thumb nail and it left a white line. I would venture a guess that it was a soft to medium Coti. On the back there is what looks like BBW - but heavily damaged. Not sure I will use this...

Does anyone know the best way to restore this Coti? i am tempted to use a sandpaper on a flat surface and lightly sand the stone down onto it (though i have chest pains at the thought of losing all that old coti... perhaps I can brush it into a pot and use it as slurry... but there will be sand paper debris as well...).

Please feel free to offer up suggestions

I have also added some mandatory pics for you to look through... though not of the razors as I stored the pics on another machine... I will post those when I get a chance as well.
Old Coticule Dishing.pdf