I think more mid than late. Around 1977, they changed the door latch handle design to a plastic handle below the control panel. In the earlier seventies, the Royal 100 had more cycle lights and didn't have a color matched lower panel.
My aunt had one identical to the one in Paul's thread with 6 cycle lights that, I think was from 1973-74.
no its not its a pic that i google but i know that my godmother that is now decise had a model similar to this one but it was a timer not buttons and lights i think that was around the 1990