Hey - I finally got to ask my boss where he got his Olds 442 parts re-chromed at. It was actually at a place in El Monte, and the prices were more in line with what you may be looking for - $250 for some thing like the bumpers, $50 for small parts like side mirrors and such.
Unfortunately he forgot the name of the place...he says he'll look. But if you Google "chrome plating el monte ca" you'll find a bunch of 'em.
Good hunting...