I recently had the opportunity to aquire a Rhodes Instructor Piano for a pretty good price. I couldn't find much info about the model (FR-7055) online, but based on the components inside and this article from keyboard magazine, It seems to basically be a mark I somewhere between 1970 and 1974ish.
I got it for a good price, but the condition is pretty bad and a few keys don't work. One is due to a broken hammer, a few have bidle straps that have been chewed by a mouse and a few seem to be bad pickups or bad pickup wiring. I've already cleaned most of the grime off with some damp clothes and elbow greese and plan on updating this page with more info as I begin to fix some of the notes.