Hey Justin,
That is the first version or original accumulator ball just as James says and they had alot of problems with them.The second version from GM is the one with the yellow silk screen and nut on it. As far as it being from a full size ( 85-86 only) Buick, Olds or Chevy wagon the only difference was the brake fluid reservoir. Slanted on the wagon (for clearance) and straight across for the Turbo cars. Other than that they were identical. I'd gladly give $100 for it. HEE-HEE just being a smart A$$ there.