Here's the continuation to what I posted earlier:
I did not find Yves Couffon's marriage to Marie Plapous, but it had to be in the 1820s. He was born at Ploëzal, FR 7 Apr 1807. His parents were:
Claude COUFFON s/o Noël & Claudine Geffroy
born Plouëc-du-Trieux, FR 29 Feb 1780
Marie-Yvonne LE BELLEC d/o Charles & Françosie Gosse
born Ploëzal, FR 20 Jul 1778
married Ploëzal 29 Vendémiaire Yr. 13 (21 Oct 1804)
Noël COUFFON s/o Yves & Marie Basset
born Gommenec'h, FR 1 Aug 1753
Claudine GEFFROY d/o François & Françoise Le Cabec
m Plouëc-du-Trieux, FR 7 Sep 1778
Yves COUFFON s/o Guy & Jacqette Le Friac
Marie BASSET d/o Vincent & Anne Jagou [or Jagon]
m Gommenec'h, FR 22 Sep 1751
That's all I could find. Trail went dead after that.
Map: Pleudaniel at top; Ploëzal at left; Plouëc-du-Trieux, beneath that; Gommenec'h at bottom right. That's your playing field.