The answer? Very long. It can take very, very long indeed.
We're making progress, though. The list of pictures is slowly growing, as is the number of references in their final format. That's not hard work, but nitpicky stuff that includes lots of looking up the missing details in the references. Final edit has been done, and there are only a few last little issues that need discussing, checking, or clearing.
Which is very good - since the clock is ticking. Soon now. Soon.