Looks like John married Nancy before the went to TX.The 1880 census Palo Pinto Co, TX:
Category: Name;Relationship to head of household; Marital Status; Gender; Race; Age; Birthplace; Occupation; Father's Birthplace; Mother's Birthplace. John A. GONCESelfMMaleW35TNFarmerTNTN Nancy C. GONCEWifeMFemaleW28MOKeeping HouseMOMO Leecester GONCESonSMaleW6MOTNMO Charles GONCESonSMaleW2TXTNMO
Have you checked the Palo Pinto Co, TX GenWeb site?Type in Gonce in their search feature and up come 4 cemeteries.Salesville Cemetery has J.A. Gonce b 12 Feb 1844, d 24 Feb 1886.Another one has a couple of married ladies with maiden name of Gonce and were born after the 1880 census.One has Lee C., 1873-1961, and so it goes.I would click and look at what else they have to offer, maybe post a query on that site, also.