The experiment was a success (I can get the amount of time required to paint an individual miniature down to about 45 minutes), but also a failure (note the "last year" at the beginning of this post!). However, I have now finished my first squad of Necron warriors, and a Necron Lord:
It's not all good news, unfortunately. I built three Necron destroyers, but managed to screw up the spray coat of silver: either I didn't shake the can enough, or the air was too wet, but whatever the reason, the destroyers came up covered in a thick blobby coat of silver, and looked awful.
So based on recommendations from my friend Mark, I performed an experiment: I gave one of the models a week-long dip in Dettol (a British household detergent):
After a wash and scrub with an old toothbrush, the final result was an - almost - stripped model:
There is still a silvery coating on top of the bare plastic, but the lumpy crud has gone, and it should be good for another coat, and painting.