|Not pictured: actual worms. Worms are shy.|
You can buy live worms on eBay. They will come in the post in a box labelled, "URGENT: LIVE WORMS. This makes me happy.
I added 300g of tiger worms to the initial mixture, and for the last few weeks I've been gradually adding food scraps for them to eat. Based on my rummaging in the dirt this morning, I'd say the colony is establishing itself pretty well. The worms are wriggling away and look nice and fat, and the organic material is breaking down nicely. The few handfuls of worm compost have been added to my soil/compost mixture (of which details to follow) along with the liquid residue, and so is ready to resume its role in the cycle of life.
I'm feeling very pleased with myself about all this. Amidst all the horrors going on in the outside world, there's peace to be found in plunging your hands into the earth, letting it get under your fingernails, and under your skin, wherever you happen to be.