at least its shiny.
HA! HA! That's about the only thing a seller won't lie about to a buyer.
...except when they say; "that will buff out".
Anyway, if you bought a 40 year old bike expecting to not work on it, or learn what makes it tick, it's your bad.
You need to establish a baseline by preforming, or at least checking/verifying, each item on the routine 3000 mile service schedule.
What speed do you expect it to idle? And what temperature is the engine when you noted the complaint? How accurate is your tach?