Got those spindles and posts painted up this afternoon, like soldiers in rows:
This shows the pins in the undersides of the spindles, and toothpicks for the newel posts:
I decided to install the railing after all the posts were in, so as to make it easier to cut to fit. Nearing the end of the line, and (after searching about for a while and thinking about how much I'd used)-- four pieces of Houseworks 7020 railing is not quite enough for this house!
Dug around in my wood scrap box and found a piece of railing of the same make that had been stained-- I'll give it an extra paint coat or two.
Whew, that was close!