Green’s Dictionary of Slang

wholly engrossed in one’s occupation.

1840		T. Haliburton Letter-bag of the Great Western i. 4: Still my attention was riveted (I fear that word is shoppy).
1864, 1867, 1870		Hotten Sl. Dict.
1874		H. Mayhew London Characters 45: A fourth or fifth-rate actor’s conversation is perhaps more purely ‘shoppy’ than that of any other professional man.
1883		Bristol Magpie 22 Mar. 6/1: [T]he [music hall] Artiste is of all men the most conceited and ‘shoppy,’ and at the same time usually the most densely-ignorant.
1889		B. Mitford Fire Trumpet III 217: What was this cowardly, egotistical, ‘shoppy’ preacher to him?
1900		Macmillan’s Mag. (London) LXXXI Jan. 222: A novel of clerical life written by a clergyman is apt to be what is vulgarly called shoppy.