The 1850 census listed him as age 1 month. Dates in that census are supposed to be relative to June 1, which would imply a birth in April 1850, but the visit occurred on Oct 1, and it is likely that the instructions were misinterpreted.

1880 census of Montgomery Co., Illinois, Irving township, enumerated 11 June, lists on p. 17 as family #145/148:
Sellers, Frank, 28, farmer, b. Ill Ohio Ill, widowed; Arch E., 5, son, b. Ill Ill Ill; Nancy B., 22, sister, b. Ill Ohio Ill.

The preceding household is headed by a widowed Delilah Lyerly, age 57. There are four other Lyerly households on the same page, including William Lyerly with wife Euphemia Sellers (Frank’s double first cousin, dau of Samuel Sellers and Ruth Beck.)

1850 census of Montgomery Co., Illinois, southwest part of district 22, enumerated 24 Sep, lists as family #705/715:
Levi Sherold, 22, farmer, b. Mo; Nancy, 21, b. N.C.; Jacob Lylerla, 28, farmer; Napoleon, 6; Francis (m), 5; Sarah, 1. All Lyerlas born in Illinois.