Bob wrote << It *would* be interesting to know where and how this usage
["mango" for a stuffed and pickled vegetable] got started. >>

According to the Browns (America Cooks, 1940, p. 115), stuffed vegetables were
called mangoes because there were few mangoes in America. They theorized:

"Mangoes make good jelly, marmalade, and preserves, but next to mango chutney
the historic favorite is stuffed mango pickles as made in India and eaten in
England. British-American ancestors of ours missed their accustomed pickle,
when trading ships from the Orient were few and far between, and invented a
number of substitutes, so that in America "stuffed mangoes" may mean green
peppers stuffed with a chopped cabbage mixture and pickled, stuffed and pickled
small muskmelons, even stuffed and pickled unripe peaches (the last two being
sweet pickles). In India nearly ripe mangoes are peeled, split, and seeded,
sprinkled with salt and laid in the sun for a couple of days, then wiped dry.
The seed cavities are filled with stuffing, and the halves are put together
again and tied with thread. Boiling vinegar is poured over, reheated, and
poured over again for four successive days. Stuffing varies, a typical recipe
being: [and a recipe follows]"

In The Recipe Book of Lillie Hitchcock Coit (San Francisco, written 1870-1880),
a recipe for "Mangoes" is made with stuffed and pickled muskmelons. (p. 44.)

Robert