Kirkhill Glass was pretty small scale, so I doubt the furnace was changed. I did poke Shiona via Facebook but got no response. Looking at my piece of Kirkhill (I know it's Kirkhill because Shiona gave it to me), your piece looks too blue. My neck glass is a very pale blue, even in the thickest bit (1 in at least) and has the very faintest hint of green. Much more like the pale blue old bottles you see.