Yes, there was a previous discussion about this:
http://mudcat.org/thread.cfm?threadid=18991

After some web surfing, my guess was that it was the townland (area of land or group of farms) of Killybawn/Killybane in Fermanagh, Northern Ireland, just west of Fivemiletown.
Killybane townland
For a closer look, click on the map tab, then click on Fivemiletown in the map. Notice that there is a waterway running by Killybane, and a settlement or area called Killybane Bridge on the other side, indicating some probable water capacity (in support of the "inkhorn" reading). I wasn't able to determine the name of the waterway.

Another alternative would be Killybern, west just across the UK border, but this seems less likely to me.

To add more confusion, in another thread, Sean McCartan mentioned (regarding another topic) that he "researched a site in a townland called Killybawn (White Church). I later discoved that in early times it was dedicated to Saint Fergus. That was in county down [...]."