Nice score for $50, time and money will make it sweet. For me that would be complete strip down resto, and not one that would make it for this season. Since it's the smallest hull, that makes it less work to get it cleaned up. Most of the bottom should polish up nice after some extensive wet sanding, may need a quart of fresh yellow gelcoat on the keel and middle, I'm sure it's chewed up. Pull the rub rails off, decals, mats, die grind and fill the rivet holes with marine tex. I wouldn't waste much time trying to bring out the white on top. Sand the crap out of it smooth and slap a fresh coat of white gelcoat on it, will run about $100 for a gallon. Strip the engine, media blast all the parts, reverse and put it together. Splurge on some cool graphics from pwcgraphics, Mike has a good selection for the X4 hulls. Hydro turf mats and seat cover in order.
Potentially a sweet little ski, like that 97', it's $50 right now, but I see a really nice ski for about a $1500 budget and some laboring weekends to get it right.