Longfield East is the civil parish - the RC parish is Langfield, which covers the civil parishes of Longfield East and Longfield West.
The NLI film references is Pos. 5765
The PRONI reference is MIC.1D/60
These include baptisms and marriage back to 1846
It's listed as Langfield (Drumquin) on the NLI parish Index.
This film also include other parishes
Shane