Most of it will be superficial so not too hard to sort. The minor stuff like nuts and bolts can be stripped and replated which will transform the overall appearance. However it does look as though the paint on the shock towers has broken through so I guess it depends on what your long term aspirations are with it. If you plan to keep it in the long run then the only way to really freshen it up would be to strip it down, clean out all the nooks and crannies, prep the rusty areas, repsray and reassemble. It's a pretty big job and then you need to consider the rest of the car too. Chances are if the engine bay is showing signs of corrosion, the rest of the chassis and suspension will be too.
I think these days Dc5 ownership is slightly misunderstood. They don't really look like a classic, yet they are approaching 20yrs old now so even the later ones will be showing signs of their age - unless they've been pampered and kept in dry storage, that is. I expect within the next 5years or so we will start to see more being broken up for spares as the owners haven't got the time or resources to restore them. The luckier ones will be rebuilt and the remaining few will be kept as garage queen's and rarely used, hiking the prices up. Based on the data on howmanyleft.com it seems this is already starting to happen - there's nearly as many on sorn as there is taxed at the minute.
