For what it's worth, that looks like the old school to me, but it looks like a reasonably recent photo, and I think the school has been there a long time. My grandmother was Agnes Paterson, one of 11 children living at Buckrigg in the second half of the 19th C, and she attended it. I pass the old school every time I call at the graveyard at Kirkpatrick Juxta, and was there a couple of weeks ago. A few years ago I think it was turned into an outdoor centre, and then the past few years looks like a private house?
I'm sure someone in the area will know better than me whether that is even the original building