Billy Ervin Estes was b. 17 Aug, 1932 in Davenport, Lincoln Co. OK and died 3 Feb 1984 in Douglas Co. NE.
It appears that his parents were Ervin Frances "Frank" Estes (1893-1965) and Mary Elizabeth Jones (1898-?)
He was 1st married 5/25/1957 in St. Louis, MO to Dolores G Wolfe who was b. 1938.
I found 2 TX births that seem to be tied to your mom: Ervin Frank Layer b xx/xx/1972 Bexar, TX to Linda Jean Layer - no father listed and Roy Eugene Estes b. XX/XX/1973 Bexar, TX to Linda Jean Layer and Billy Ervin Estes.
I found 3 TX marriages that may be your mom:
Linda J. Layer 22 to Gerald D. Chisum 26 on 2/27/1971 Bexar, TX.
Linda J. Layer 24 to Billy E. Estes, 40 on 3/8/1973 Comal, TX
Linda J. Estes 33 to John R Miller 28, on 11/28/1981 Bexar, TX
There are several trees at Worldconnect that have Billy's family - I suggest you contact the tree owners - they may be more willing to talk about Billy.