An IBM (no model number) two internal side-by-side
black 3.5" floppies,
non-standard monitor connector, PS/2 style mouse & k/brd connectors,
small grey box, about the width of a normal keyboard, 5" high, about 12"
deep. On the rear "Manufactured by IBM Japan 1987" nothing else.
Sounds like an IBM PC JX.
Apparently when the IBM PC JR failed in the US market, they sold the design
to IBM Japan who revamped it, called it the JX and sold it in places like
Australia.