Green’s Dictionary of Slang

1. (Aus.) in good spirits, cheerful.

1871

Hamilton Spectator (Vic.) 7 Jan. 1/7: If you ask him how he is, he is ‘all serene,’ ‘jolly,’ ‘ highcoct’ ‘ spotty ;’ perhaps he may be ‘out of sorts,’ ‘down in the mouth,’ ‘seedy’.

2. inferior.

1960		P. Rabe Murder Me for Nickels (2004) 26: All those juke owners – their deliveries faulty – reaped only the spottiest income.
1967		M. Frayn Towards the End of Morning (2000) 8: They’re a spotty lot of pix, anyway. I don’t care what spotty caption you put on them.