Not quite!

Wee Rover just phoned me (not about the song, he's down here this weekend and we're meeting up for a pint and a trad session in the Lorne Bar, Dunoon. Unlike me, he's a fine guitarist and a wonderful singer).

He reminded me that "Kilbowie Hill" is in Ewan McVicar's book, "One Singer One Song" and he does indeed spell the place name as "Cochnae". Both wr and I have the book.

Looks indeed like a "scottishization" of "Cochno".

So mystery finally solved: it's "Cochnae", tho, as far as I'm aware, Andy Hunter is the only Bankie ever known to have used that form of the name!