I know a bloke near me who specialises in taking older machines off businesses and he's got a garage full.
Literally chock a block and it's always fun to go down there and have a look around.
Got this case from him a while back, an HP d530c with just the Compaq PSU inside.
Unfortunately it doesn't have the slide-on motherboard tray or backplate, so I'm having to improvise.
I've always been astounded at the quality of HP stuff and the case alone must be about 12kg or more in fact.
The PSU is slightly smaller than usual atx, so fitting anything other than an HP 240w won't fit.
It all comes up nice and shiny after some soapy water, except the nicotine stains which are not so easy to get off.