Very good condition OEM part, pictures tell the story. Has turned lighter over time from sun exposure, with slight fading to the Nardi logo piece.
The melted rubber insert around the crown (they all turn to gum eventually!) was just removed and replaced with hard rubber O-rings that will stand up much better to heat and sun, a time-tested solution figured out years ago here on miata.net.
The early BRG Evolutions are slightly nicer and just a hair heavier than the later M Edition Evos, since they have a threaded metal core (and redundant set screw) covered by a flexible rubber cap, rather than the hard plastic inner core found on the M knobs. Of course, either OEM version is preferable to the aftermarket Evo without threading, which never quite stays in place.