Hi Thomas,
in my 170Sb from 1952, which is in original condition, the steering column is in the same black colour as the whole car. Not chromed. Also in cars owned by some friends of mine.
But however, I've seen some 170 with chromed steering column, and not only this: Their owners chromed almost everything in the engine compartment. This is not original and looks horrible in my opinion.
But the gear shift lever is chromed in original (cars with steering-column gear shift only), instead of the knob, which also is in black colour.
Kind regards
170Sb-Fahrer