You will love your 99, they are the handiest things to have around. Be sure to check the wiring and make sure there are no bare spots or cracks. No need in having a chance to be electrocuted.
Nice thing about your machine is that you can readily find parts for them. And the 66, 99, 185's are all the same as far as the bobbins, bobbin assemblies, throat plates, and needle plates. And when you clean it up leave the little red piece of felt in the bobbin assembly its for oiling the lower half of the machine.
Billy