Best car leather colour restorer!?

[PorkRind]

My merc seats have some fine scratches on them and before it was sold to me it was. A bargaining point.

I'd like to know what product is best to restore the black colour and remove the fine line/creases in the leather, I think the best thing I could find would be :

https://www.furnitureclinic.co.uk/Leather_Recolour...

What are your experiences and what would you recommend, thanks..