As part of my research for the talk I gave at jsconf.eu 2018, I bought a ZX Spectrum 48K. I purchased the machine from eBay, but it was indeed an original 1980’s Spectrum with a few internals cleaned up.
In fact, it even came with the original manual which I had long forgotten. Except the manual isn’t a manual at all (in actually fact, it never even claimed to be!).