Today I figured out why I had stalled - fear of cutting the fashion fabric. Which, of course, is silly.
Having talked myself out of this state of mind, I have cut the fashion fabric and started construction. I decided to line the dress with the lime green muslin I had made, for 2 reasons: the fashion fabric is a light cotton and needed some stability and opaqueness; and I forgot to draft new facings when I altered the pattern.
I am up to inserting the zip - a job best left for another day I've decided. Then I can finish the armholes and hems. If I can keep up today's momentum into the next few evenings, I might be able to wear my new dress to work before the week is out. I just hope this lovely, sunny, warm weather we've had over the weekend holds until the dress is done!