Green’s Dictionary of Slang

good; thus ream bloak, a good man.

1859		Hotten Dict. of Modern Sl. etc.
1860		Hotten Dict. of Modern Sl. etc. (2nd edn) 199: REAM-BLOAK, a good man.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 313/1: Not one ‘swell’ in a score would view it in any other light than a ‘ream’ (genuine) concern.
1870		Hotten Sl. Dict.
1888		Hampshire Teleg. 31 Mar. 11/5: A petition fortified with ‘ream monekurs,’ or genuine signatures, will come to eighteenpence.
1937		Lil Hardin Armstrong ‘Born to Swing’ 🎵 Old man river can roll along, pick cotton with Georgia reams, / But I’ll roll my eyes and pick cute guys.