Lim - you could try Swift #5 LEATHER RESTORER (RM22) Available from Jaya Jusco. It is good for old and frailed leather, but dont expect miracles. Alternatively, BMS has new steering wheels for about RM600-00. Changed it for my brother and myself - quite pleased with it.
But be careful when wet-proofing steering wheels. Dont want to make it too slippery.
Let me know?