It looks like you're new to this forum. Also, since you're asking this question, you are probably just learning the sport, am I right ?
If so, then the best advice I can give you is to throw it in the bin.
Regardless of it's condition, this kite isn't worth anything anymore.
Hopefully you didn't pay much for this.
A 18 year old kite C-shape kite would be increadibly difficult to learn with. The safety system would be either non-existent or extremly outdated (very dangerous). A kite like this would be very difficult to relaunch. You'd be very lucky if it's not leaking (regardless of it's condition).
Don't buy used gear without an expert shopping with you... read this story here:
www.seabreeze.com.au/forums/Kitesurfing/Newbies-Tips-Tricks/What-to-look-for-when-buying-usedHopefully you have more budget as well as kitesurfing isn't a cheap sport. Equipment has drastically improved in the last 20 years.
You can find more tips on our blog:
www.kitebud.com.au/6-things-to-look-at-when-buying-a-used-kite/www.kitebud.com.au/how-to-choose-a-kite-size/hope this helps
Christian - KiteBud