I know roughly how to put one together I reckon using 3 plastic storage bins and some plastic mesh but it's making em worm proof so the wriggley wee buggers can't escape and tbh, the inclination to actually build one, I've got the storage bins just need a tap for the reservoir and paint to coat them in to stop light getting in, I'd like to get one up n running as at the mo all our vegetable type food waste goes on the compost heap.
It makes good compost but worms are far more efficient at it, plus you get the liquid concentrate too. I'll have to look into it more, so much to do so little time to do it all...
Have a word with your local plumbers, when they get hold of some plastic cisterns ask them to save you one, then get some of those plastic crates with small holes, local indoor market might have them, then put it all together to make your wormery, but make sure you take photos and make it into a tutorial so there will be two of us doing them
We got one last year free from the council with the worms coming through the post. We set it all up and proceeded to kill them, either through situating it in the wrong place in the garden over from over feeding or even a combination of both
We will start again this year and see what happens.