Not much is known about this machine other than it’s based on a 1Mb Macintosh Plus machine, it’s completely custom made in around 1986 and it does not work.
It is built to a really high finish with injection moulded plastic and really finely cut steel and aluminium, but it doesn’t have a single label on it - nothing to be able to tell who made it and why.
Inside there is a Macintosh Plus motherboard and analog board, with a custom adapted SCSI hard drive, floppy drive and some controls such as reset and either volume or brightness. There is also a serial output on the back, which suggests this had some kind of industrial use.
The previous owner was given this about 5 years ago and was told it didn’t not work.
Interesting... I would start where I'd start troubleshooting a Mac Plus... Check the power supply voltages, make sure the SIMMs are seated. Check everything obvious like that.
Next I might buy a working Mac Plus. They're common and fairly cheap. See if swapping the analog board and/or motherboard from that into this makes it functional. Mac Plus are kind of a dime a dozen, Apple made a LOT of them. This is rare and interesting.