Touching up fur color

[Taffy Saltwater]

I got a couple of vintage beaver capes that have oxidized & lost some color on the edges - from black to red.  Is there any quick & easy fix to color the light areas back to black?  Since one is from the 60's & one is prior to '57 & they are both backed w/satin I don't really want to dye it.  Any ideas?

[Dinobabe]

Hair dye?

[FortuneRose]

What about hair stains?

You would have to rinse the fur where you apply the stain but wouldn't have to throw the whole thing into a machine or tub for washing.

And I say stain instead of a dye because it is less harsh and requires less processing and has less steps than a dye would.