Yup, it's an SR800 in Ebony that looks to be all original except the LOOK pedals (see attached catalog page).
One year before the SR800 was dubbed Black Lightning, it was just a bike ridden "by many of the swiftest bike messengers" and available in "sinister black on black".
Nice find. Hadn't heard about it. Makes me want to the hear the story behind it becoming "Black Lightning" in 1987.
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WTB: Slingshot bicycle promotional documents (catalog, pamphlets, etc).
WTB: American Cycling May, Jul, Aug, Oct, 1966.
WTB: Bicycle Guide issues 1984 (any); Dec 1985; Apr 1994; May, Jun 1996; May 1997.
WTB: bicyclist May, Dec 1997: Jun-Dec 1998.
WTB: Bike World issue Jun 1974.
WTB: Litespeed head badge (circa 2000)