>>2009363usually i'd say that's superficial rust and don't even worry, but the problem you have is the threads are quite long, going off the minimium insertion mark of a quill stem you probably have your expander wedge sitting on those threads, and, on a ritchey i bet the tubing is pretty thin too.
The best way to remove the rust would be to place the steerer in a jar of evaporust. And then run a die over it. You can make a die by cutting slots in the thread of a decent sharp headset lockring. The holes in a tape/die are where waste material and gunky crap can escape.
On install just liberally grease the inside and out of the steerer tube and it should be fine.
And you will want to get a technomic or something which can place the wedge on the non-threaded part of your steerer.
