Judging by the control panel it looks like a late-70's machine, but with Frigidaire 1-18s I never know!! The control panel looks like it's in very nice shape (not eaten alive by Spray & Wash as mine was!) as well.
Very interesting that your WIG appears to be basically the same as the WC, with the exception of the markings on the control panel! My water level selector is a little different, and lacks the Jetcone diagram.