Getting the time to finish it is the hassle. The "What plant built what and when" chapter is actually finished. I've been invited down to a Rare Spares discussion day in february, so I hope to get to see Leo Pruneau when i'm down there, and interview him as an opening section for the book.
I also scanned a massive amount of release HJ information yesterday, for appendicies for the book. I'm still very light on HX and HQ info, hoping to get all that next year.