MIAMI — A legal fight is brewing in Florida between the estate of Eliot Ness and an Ohio company over some long-undiscovered stock that apparently belonged to Ness and may be worth more than $1 million.Ness, the famed Prohibition agent who led the “Untouchables” in their crusade against Chicago gangster Al Capone and his mob accomplices, later was the top executive at bank services company Diebold Inc.A 50-share Diebold stock certificate, along with Ness’ old federal badges and credentials, languished for years in a box …