Hi LGee,
Given that the family apparently believed that they came from Kerry, I wouldn't be discounting Inchinascarty yet.
Especially as the place on your scan begins "Inchanasca ..." which could easily be a rendering of "Inchinasca ...". It
looks the same - and doesn't look like the beginning of the townland of "Inchcauascalla" in Limerick.
Of course, I don't know how they'd be pronounced in Ireland

And the "e" at the end could easily be rendition of "y".
That would leave the "ll" to be explained. Does the Registrar cross his/her 't's - or could it be "lt" which could sound the same as "rt"?
It might be worth looking at the Griffiths Valuation to see which surnames occur in these two townlands (the Limerick one rendered as Skoolhill in the GV).
A quick look at the failteromhat site shows Foley, Herlihy and O'Donnell in the parish of Dromod but, of those names, only O'Donnell in Fedamore.
Regards,
JAP