For that money, I'll live with the ticking!
I just blasted the worm gear to get rid of it

Any s2000 owners suffered badly with rust? Looking it up for someone and it seems that it's a contentious issue on whether it's worth bothering with due to the double skin nature of the rear end. I presume any AP1 with no rust showing has been cleaned up at some point by now?
Not necassarily, depends on how clean it's been kept. Generall the rear arches go because they're mud traps which hold the moisture in. A good job can be quite expensive, but if values are holding or going up it might be a worthwhile investment.