I finally finished this on the 12th of March 2016. Here's what it looks like!

Stencilling should be done with sponges and not regular paintbrushes. I had to learn this by experience.

Not only can it take the weight of a toddler, it can take the weight of two toddlers and one me, making it strong enough to support 80kg+!!

And the kids loved it, so it was a job well done. The end.

[2021 update: it's a useful seat for the boys to use when they are watching me play Commander Keen.]