Green’s Dictionary of Slang

to hawk goods in the street; thus handseller, a street or open-air seller.

1859		Hotten Dict. of Modern Sl. etc. 48: handseller, [...] a street or open air seller, a man who carries goods to his customers, instead of waiting for his customers to visit him.
1864, 1867, 1870		Hotten Sl. Dict. [as cit. 1859].