1855–1872
It took seventeen years. The work was driven by Fr Joseph Grégoire, whom his chronicler calls the apostle of Vadakenkoulam, and the building was engineered by a Jesuit lay-brother named Joseph Bergenthal, whose office the Society's Roman register for 1872 gives in two words: Ædif. eccl., builder of the church. Between them they turned twenty-four arches that carry their own weight, in lime and palm-toddy mortar, without cement, without iron, and without one wooden beam holding anything up. Halfway through, in 1861, the bishop came again, and three thousand Christians were waiting for him on the road.
What this source establishes
The 24 arches, the 12 over the altar, and the chunam-and-toddy mortar. All of it is the parish's own account of its own building — published because it is the parish's account, not because anyone outside has checked it.
This is as much of the book as this site prints. It is named in full in the bibliography below.