too much rust (torsion bar)
 

My rear torsion bar is rusty. I've used a wire brush to scrub off some of it, but there is still plenty more. What do you think?

http://forums.pelicanparts.com/uploa...1405432756.jpg

My first thought is to clean it up a little bit more, then paint it with a rust protection paint.

That looks borderline between tossing or refinshing. Your reference to 'late apexing' in you handle suggests that you use your car for purposes other than commuting, groceries, and cars & coffee.
If it were me and I depended on these parts on the track, I'd replace. You can also re-use it and wait for a FS ad for the bars that you need. Who knows, maybe even upgrade/upsize while you're in there.
Bill K

I''ve got a pair of 31mm hollow tarret bars that were used once, literally, before the car was swapped over to coil-overs, email me, and I'll send you some photos.

This is a 31mm hollow bar. The car is used only for club racing. I haven't taken the one out from the other side yet.

I have 23mm front, 31mm rear. If I replace, what would be the upgrade?

I wouldn't get aggressive with its surface. I'd just oil it

I don't know about torsion bars but I have seen more than one guy with good intentions sand blast a set of coil springs- inadvertently relieving them of their tension

And you have to remember the torsion is on the outside of the bar.
Bruce