Green’s Dictionary of Slang

wonderful! excellent! perfect!

1987		‘Victoria Parker’ Pay for Play Cheerleaders 🌐 Chris with the perfecto ass, and Nancy with the big titties, walked down the hall at Valley High.
2001		K. Sampson Outlaws (ms.) 134: I’ve got the cunt’s own personal emergency-use hotline number, haven’t I? Perfecto.
2005		Mad mag. July 35: Perfecto! Did you bring my fee?