Following up that fantastic NS400R is a 1999 Aprilia RS250 located in Monrovia, California. The bike is a track bike and has a California Off-Road title (I wonder if they use the red/green sticker system for things other than dirt bikes). Sellers description of the bikes condition:
There are a couple small scratches on the left side of the swingarm. There is a small nickel size ding in the right frame spar. The paint is clean but not perfect, after all it's a track bike. Otherwise it runs great.
There appears to be no spares included which is unfortunate but they can still easily be had. The asking price of $4,200 is consistent with other track RS250s we've seen. See the bike here on Craigslist.