FOUND!

I found them! Three Pest Control Guys hadn't found them and two separate treatments hadn't killed them. I couldn't find the nests even after taking the bed apart - literally. I took some scissors and cut the ensemble base open, but we didn't find them until we tipped the base up on its side. Check it out!

This the base of our ensemble up on its side.
It has nine castors: little wheels that screw in.

Sadly, there is a little square of thin cardboard between each castor and the bed. And bedbugs are known for nesting in books, so I guess they liked these cardboard squares.

And they love living in the dark under things like sewn-on labels on mattresses or between slats and bed bases. So this was The Ritz for them.
All the classic things we've been searching for. Shed skins, mess, spots of blood (maybe they drink too much of my blood and throw up a bit?) and bugs.
And the Pest Control Company, bless them, came right around for some Bed Bug Genocide. Well, Pesticide anyway. Dead, dead, all the bed bugs dead.We're still sleeping on the couch, but we're sleeping easier. Soon we'll have a new bed, a pest-free room, good nights' sleep and I might, just might, have pretty legs again. Well, you know...