Ok what you have is called the "L" drive, basically a outboard power head and lower unit with an I/O style midsection. These were only around for a few years and parts are getting rare to find.
I believe the power head was made by Force which has been out of business for years. I would first focus on seeing if it runs and or if you can get the parts to make it run as there are no cheap non-custom repower options.
Normally I would recommend to stay clear of this boat but since its already yours I guess you'll find out if you got screwed or not.
1997 2400 SCR
5.7 Vortec / Bravo 2