No.
It is clearly a Frankenstein watch. This is a 1985 watch due to the smaller case size with a 1980/81 early dial put in.
It’s the wrong case size for a 1980 watch, the movement wouldn’t fit in and the battery hatch would be too small for the required 368 battery. Don’t know if a 1985 case back would fit on a 1980 Fatboy.
Not sure why the seller has done this unless they don’t know what they are doing or they just have a large collection of parts.