I've not really done a lot on the Cowell side - more Caine and Kewley.
But there was a gathering of Cowells a month or so ago and the family tree was mentioned then - Jill told me what she had which is likely to be similar to yours.
I was interested because in the various census they seem to be living, if not in my house, very close at Ballaragh.
If I get chance I'll have a look before you get here.
Will let you know if I do.
Viv