I'm adding some more information to Dr.JB's interesting mail.
* Chozhan kochchenganan built 74 madak koilgal for lord shiva on the banks of cauvery. He finds a mention in thirumangaiyazhvar's thirunaaraiyur pasurams - "Thirukkulathu valar chozhan nirai maadam seermingale". He was before vijayalaya.
* Sundarar in one of his hymns says that he met pandiya king in madurai and at that time a chola king was also present in the court. We are not sure who this chola is - but the dynasty was alive.
We need to do proper research between sangam cholas and vijayalaya period, identify different references and date them properly.