Yaa, Thiruvarur Temple I have some information: Its was build ( restructured) by a women called Paravai Nachiyaar , she is basically a thevardiyar, lived in the period of Rajendra Cholan, Paravai got friendship of Rajendra Cholan and with his help she converted the temple, before that it was Sengal temple ( i Mean ordinary Stone) .
Even today we can see inscription and more she donated a BIG Brozne Lamp to the temple thats also still there.
Chistle is the Iron instrument used to break/shape rocks using a hammer.
Its similar in shape of a 'crowbar' but very small in size, just fits in palm...A sculptor holds a chistle in one hand and a hammer on the other, and hits the chistle to break the rock and shape it.
Musukunda Chakravarthy The Legend is - Once Shiva and Parvathi were sitting under a Bilwa tree. A monkey sitting on the tree unknowingly plucking the vilva leaf and dropping down, which fell on lord Siva. Siva was pleased with the Vilvarchana and gave a boon that the monkey will be born as a Great King. The Monkey requested him that he be born with the face of a monkey so that people in the world ( Boolog) realise the benefit of worshipping Siva and understand even a monkey can become a king with the grace of the lord.
His image is in a pillar - dont remeber the place.
His minister's name was Amudogar who built the Alangudi siva temple ( Gurusthalam) regards