Restoring a Leather Sectional

I have a very nice, comfortable leather sectional. It's in great shape except for all the scratch marks my dog has put on it. I'm wondering if there's some way to retain the marks, kinda like one would touch up wood furniture. Is there an "Old English" for leather? Or could I use some clothing die and rub it into the leather?

A couple of the cushions are really scratched and look old, but if they were restained, I think the sectional could look new. The arms and the back of the sectional are in great shape. I can't afford to buy a new one of this quality and comfort, so I'd like to restore the color to these cushions. Has anyone done this before? Any ideas?

NancyAnn