Treating very small amounts of surface rust?
 

A frame I'd bought on eBay just arrived. As expected from the pictures, the paint is a bit banged up, but there doesn't really appear to be much in the way of rust (hooray for chroming under paint) and thick paint. Once I get it home and have a chance, I'll be hitting the interior with framesaver just to make sure. The one place that I did find rust was on the inside of the race number tab (is there an official name for this thingy?). Is there a good way to treat this? Seems silly to make an oxalic acid bath for this tiny circle that's all orange, but I don't want to let it get any bigger. Do I just try and use steel wool or something to get the rust off and then hit the area with a little bit of touch up paint?

Also, how visible/feelable should the helical ridges of SLX be? The frame should be SLX and the decal says it is, but I didn't see any ridges inside the head tube or top of the seat tube just looking quickly. I highly doubt that it's a fake/repaint, so I was just wondering if the rifling is more subtle than I was expecting and I should look more closely.

Naval jelly (suspended phosphoric acid). Careful not to leave it on there too long or it can discolor paint.

+1 Naval Jelly. I also like Barkeeper's Friend, in powdered or liquid form. Works fast on small surface rust areas.

Hmmm, I think I have liquid phosphoric acid (along with hydrochloric, acetic, nitric, sulphuric, and trichloroacetic) in my lab. Probably too concentrated to work and should stick with something known though. Do I just get some of that and dab it on with a q-tip or something? The inside hole of the number tab isn't a big place to do much in the way of scrubbing.