Thank you for the reply.
I too had come to the same conclusion, but wondered if anyone knew for definite. I have plenty images of Craiginches yard in '63 and '64 not showing the elevator building, but can only find images from the 70's with it there. My model railway layout is set in 1964, and in a different location, so I think if I depict the cement terminal as being brand new, it might be plausible.