Hi Loola, That looks like a 1996 model Kona Cinder Cone, if I'm not mistaken. The Cinder Cones are fairly desirable because they were made from lighter tubing than the lower models and sat a decent way up the Kona range - they were a lot of money when a summer job at McDonald's paid £2.50 an hour.
The wheels, chainset, headset and seatpost all look original. The handlebars and stem are higher rise than it would have originally come with. It would look cool with basic set of flat bars IMO. The seat looks like it's from the late 90s, so pretty good for that bike. Brakes and rear mech look like late 90s upgrades too. The forks look like Manitou Spyder with (if it's possible) Rockshox Quadra 21R adjuster caps! Maybe this is because, as somebody has already said, the Spyder top caps used to break easily.
Manitou used to make drool-worthy forks but lost their way in the late 90s and made forks that looked 'budget' even though they worked OK. This, combined with the poor DIY paint job on your forks makes them look really tatty but they could be refurbed and on the plus side the elastomers all look intact. So... £50 for the whole bike? That's fair enough. I'd clean the fork internals really well, re-grease them, clean/lube/adjust the rest of the bike and go have fun on your new Kona.
Rich