Looks nice but that's an aftermarket master cylinder.
NOS 71-'74 master cylinders I've had were coated with a gray coating, body, bale wire and lid. For lack of a better description I'd call it a parkerized finish.
Only exceptions I've seen were the carry over "9191" disc brake master used on '70 and '71 hemi E and B bodies, and the 72-74 manual disc brake master cylinder, both of which were painted black, including the bale wire and cap.