The red switch button on the light looks like the modern replacement lamps I've seen for sale. I think it's a genuine 99 or 99K body that's had some replacement parts put on it over the years.
I have a pair of 99K's that are slightly different from each other; they look like they are pretty much identical to the newer two that Macybaby posted. One of them is missing its lamp and I was hoping to find the spotlight style to replace it but all the replacements I can find look more like what's on your machine.
They're darling little machines though - even with replacement parts she's a cutie and I think you'll like sewing on it once you get her all cleaned and happy. I like the decals on yours, mine have the simpler decals but I like the flourishes on yours.