Agnes Costley

Yes this is weird, considering James's grandmother is also Agnes Paterson, but this is according to records of a mother's maiden name Paterson (Costley, n.d.; Scotlands People, 1878).

Sources

Costley, J. (n.d.). Family Register: James Costley born 1878, April 14, Glascow. In The holy bible [Family bible]. W.R. M'Phun.

Scotlands People. (1878). James Costley. In Statutory registers - Births.
https://www.scotlandspeople.gov.uk/