Hi,
I have also had a look at your Griffith reference and you are correct. On the map the thick red line is the border of the townland and the thin red line is the border of the land which John Johnston rented from the Rev. John Bagot, possibly part of the church Glebe. John Johnston also rented two houses as well as barns etc (Offices). He let one of these houses to William Kane who may well have been one of his farm labourers. One of the black dots within the red boundaries, along the Cavan Road, would have been William Kane's house, 13b.
Regards