There were two Catholic Chapels in the area back to at least the 1840s - one adjacent to the townland of Aughamore, and the other at Knock (OSI 1st Edition Maps). The parish was listed at that time as the district of Knock, or 'Knock and Aughamore', which would suggest that Knock was the principle church at the time.
There doesn't seem to be a graveyard beside either church
EDIT : found a graveyard a short distance about half a kilometer to the north of the Catholic Church (now dedicated to St. Joseph) in Aghamore - see Google Street view and 1st Ed. OSI Map (c1840). The graveyard is within Aghamore townland and also at the location are ruins of an old church. It may be the location of an old pre-reformation Church, so a shared graveyard.