A book I own "Northern Virginia Heritage" by Eleanor Lee Templeman & Nan Netherton has a little bit about Moncures.
Page 16 - "The well-loved John Moncure suceeded Alexander Scott as minister (of Overwharton Parish) and was responsible for the building in 1757 of the beautiful Aquia Church which is still standing."
Page 18 - "Union Methodist church - at Falmouth, on a hill above the river east of the highway stands a church facade and tower of sturdy brick, but no church building remains.This church was probably the outgrowth of Greaves chapel, founded by the Reverend Moncure Daniel Conway, first a Methodist minister and later a leading Unitarian pastor in Victorian London.(I don't know what this means after the name Moncure, there is no comma; I copied it as it appears in the book; there is a picture of the church.)
"Same page - Serving Overwharton Parish, which was established before 1680, and replacing a church built in 1751 which burned three years later, the present church was erected in 1757.It has a rare triple-deck pulpit.The Reverend John Moncure, rector from 1738 to 1764, is buried beneath a stone bearing the inscription; 'In memory of the Race of the House of Moncure.'"(There is a picture of the church.)