Green’s Dictionary of Slang

1. a seller of bad potatoes.

1859, 1860		Hotten Dict. of Modern Sl. etc.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 24/2: They are all known one to another by nicknames [...] ‘Spuddy’ (a seller of bad potatoes).
1873		Sl. Dict.
1882		G.A. Sala in Living London (1883) May 186: I find ‘Spuddy’ given as a seller of bad potatoes, while ‘spuds’ are defined as a low-life term for raw potatoes.

2. a seller of hot baked potatoes.

1984

Partridge DSUE (8th edn) 1135/2: late C.19–20.