Green’s Dictionary of Slang

(orig. US black) something or someone admirable; also as adj.

1920		‘The Bullin Mr. Stavin’ Chain’ in J.F. Dobie Rainbow in Morning (1965) 179: Well, you kain’t make it down / Like the bullin’ Mr. Stavin’ Chain.
2000		(con. 1940s–60s) Décharné Straight from the Fridge Dad 22: Bulling Something good, mighty fine.