[GreenKeys] Rejuvenating the platen on 33?

[Charles]

The platen rubber on both my 33 ASR's has become very hard and the  
surface is quite smooth. So despite the appropriate pressure from the  
small spring-loaded roller in the front, neither machine will reliably  
line-feed especially in cold temperatures that my shack is now  
experiencing. The platen is turning, it's just not grabbing the paper.

Is there something I can apply to the rubber to rejuvenate (soften)  
it? Or would coating the surface with a frictive material be an  
alternate fix?

thanks
Charles