Great lookin', Royal6.
Mine is a WE4 so I am torn as to whether or not to replace the trim with chrome. I have a grey leather limited set of seats so they are going in. Chrome Wheel lips, window surrounds grille and bumpers could be in its future.
As far as the WO2 black out goes, according to Buick literature it was available with black until the WE4 was introduced. It is not clear if the black with standard chrome was discontinued then or not. Either way they both would have had chrome bumpers from the factory. Black bumpers were only available on WE4 and WE2(Grand National).
As far as stainless rocker trim and cornering lamps, these were not available with the WO2 blacked out trim. Though the chrome non remote mirrors were for some reason. Most came with body color sport mirrors.