Great news... The PCs were installed yesterday and today my (excellent) volunteer and I started restocking the non-fiction stock. I was glad that the calculations had been successful and we had ample space. The sequencing does seem logical, well to me anyway - trust me I'm a Librarian!
The next task will be putting the fiction into order and shelving this, but for various reasons (too trivial to go into detail here) won't happen until the week after next.
It's starting to look good though, isn't it?