1855
Fr Grégoire got the plan accepted in 1854, and it was not easily done. On 9 August 1855 the bishop came and blessed the foundation stone of the church that stands today. One of the priests made a motto for the design, and it is the whole building in four words: “Templum sit duplex, ara sed una.” Let the temple be twofold, but the altar one — and that one altar for all. Two naves would open apart at their doors and lean toward each other down their length until they met, and where they met there would be one sanctuary and one altar, for everyone who came in at either door.
What this source establishes
The motto, transcribed only in parish-side books. The transcription is textually corrupt (the second clause, "tribulis ingemnis", is not Latin), no one has ever inspected the stone, and the parish's own compilation says only that a priest COMPOSED a Latin verse — not that anything was engraved.
This is as much of the book as this site prints. It is named in full in the bibliography below.