I think I got the hang of this Thursday . . .
Finally got the scene sent off to the Dustbowl musical (as I mentioned) and then did a whole buncha work on Book 1.10. Overall, I wrote 19 pages today, which is more than I've done in a long time :)
I also found time to rehearse and to play with the ratlings quite a bit, not to mention draw a sketch for "Romeo x Juliet" and I just started an "Alice in Wonderland" one. I'm really enjoying drawing again, because it's something I'm just okay at, so it doesn't set off my perfectionism, because I know I'm doing it just for fun. But at the same time it stimulates my brain creatively in between writing sessions in a way that, oh, say, iPad games and idle websites don't necessarily.
Book 1.10 is a sensible 62 pages and 11,592 words, which is basically on-track for where I am plot-wise in comparison to the last draft from which I'm still working.
Meanwhile, I'm on page 250 out of 326 on Book 5.3, which is SO SO CLOSE, but I think I'm once again suffering from spiral syndrome (ie my tendency to exponentially decrease the speed at which I can work the closer I get to the end of a piece, apparently even in editing). Hopefully I'll have a new perspective on it tomorrow and can really nail it down. It's just so much more fun to play than to edit, so I keep jumping ship to 1.10 :)