1980 Tyres skinwall part dried out..anything i can do?

[Brandy Truffle]

Got set of 1980 tyres that came on a survivor,tread is virtually new,but the walls have dried out in places.
Is there anything i can do to improve appearance,tidy them up some?

Any sort of chemical i can put on them to bring them back (ish) to life and give them an overall same colour on the skinwall?

 

[MartyC]

A few people have tried Wynns Tyre Cleaner, someone once told me linseed oil is also good but I've never seen it used  .

http://www.amazon.co.uk/Wynns-Tyre-Clean-Sheen-750ml/dp/B0001P1AYE/ref=sr_1_11?ie=UTF8&s=diytools&qid=1199832454&sr=1-11