As is customary in all of my projects, a cheap 40$ ATX 'donor' case is stripped of its motherboard backplate/expansion slot sheetmetal, the CDROM and hard drive brackets, and the powersupply. Pop-rivets are defeated by drilling out their center with a 1/8" bit. The 'power' and 'reset' switches can be very handy, as can the LEDs. This time I used a full-tower case that came with swivel casters (wheels) - so I grabbed those, too.
The first step was to fit the sheetmetal thingy that holds the motherboard and expansion cards. Hopefully, on your donor case it is a separate piece(s) from the 'body' of your donor case - a "swing-out" mount is best.
I adjusted the position of the bottom wood shelf so that the sheetmetal bracket would fit into the opening. The motherboard tray extends across the entire length of the side of the table, by pure luck mostly. The rear of the table will need to be "cleaned-up" by framing the opening with aluminum angle stock and fitting panels made from aluminum roof flashing. While I was back there, a provision was made for
mounting a standard case fan...mostly because I had a pair of chrome fan
guards begging to get used.
This sure doesn't look like three hours worth of work