Just so there is no confusion, the New English Dictionary is the OED.
The Century Dictionary, published 1889–91, defines jumper as:
A kind of loose jacket with sleeves worn by some classes of laborers, as seamen or stevedores, usually with overalls, reaching to the thighs, and buttoned the whole length in front; also, any upper garment of similar shape.
But it includes this description of a pullover (a hoodie) as a usage citation:
Men and women [Eskimo] are alike clothed with jacket and trousers. The jacket is a hooded jumper with openings only for face and hands. —A. W. Greely, Arctic Service, 32
And there is this second usage citation. I’m not sure what it’s describing:
A green-check cotton waist or blouse sewed into a belt—the masculine uniform of Fairharbor; he calls it a jumper. —E. S. Phelps, Old Maid’s Paradise
The Dictionary of American English (1942) defines it as:
One or other of a number of variously styled garments, esp. a jacket or blouse worn over a shirt, guimpe, etc.
The DAE includes a 1850s citation from Elisha Kane’s The United States Grinnell expedition in search of Sir John Franklin.: A personal narrative.
Kane’s Arctic explorations: The second Grinnell expedtion in search of Sir John Franklin includes this illustration.
Based on these early definitions and descriptions, I don’t think we can say that the word every referred to a very specific type of garment. There has always been some leeway in interpreting what falls within the category of “jumper.”