Hi, I quote here a reference from the same book which I am referring for my current Pallava study. Dubreuil, in the conclusion of his book, states that there are references of structural temples before the period of Mahendra. Though much of the research was already done however he decided to try his luck. He quotes that he found a mandapam which was built of stones collected from various places in Ekambaranathaswamin temple. Many of the pillars were in Pallava style. On one of the pillar he found an inscription where many birudas of Mahendravarman were engraved like Abhimukha, Chitrakarapuli, Vambara and Kurrambu. Chitrakarapuli is found at Pallavaram and Kurrambu, Vambara & Abhimukha found at upper cave at Trichy.
Location of this mandapa - Temple priest call this Paurmani Mandapam. It is in second enclosure of the temple and is tacked onto the thousand pillar mandapam. It is to the west of grand gopuram which serves as the entrance to thousand pillar mandapam. This grand gopuram is called Palli gopuram. Paurnami mandapam has a facade of 6 pillars which are probably of Pallava origin. Only one pillar has inscription.
If anyone is in Kanchi, can it be verified? I am not sure whether this inscription has been published in EI/SII or any other official epigraph series.