tsuwm mentions this word down in Miscellany, but does not discuss it. Since you are so fond of Bulwer-Lytton, you might enjoy commenting on it.

Rather it's a more old-fashioned kind of story -- a graustark novel. There was once quite a fad for novels like this, beginning with George Barr McCutcheon's novel Graustark in 1901. Graustarks are novels set in imaginary -- but contemporary -- European kingdoms, where royal families are riven by dissension, lost heirs struggle to regain their rightful place from usurpers, and tourists find that they are exact doubles of royal personages


Indeed, I am a Bulwer-Lytton fan, and I intend to investigate further posthaste! (after errands...) Thanks, wwh!