LEDs have been around a long time. There were red ones in the 60s and the rest of the colors came along at various points in the 70s. They didn't become common in consumer devices until the 80s but if you consider dude supposedly build a time machine, you have to figure he did some pretty beyond the edge stuff in there. 
Yes, but those used on the Flux Capacitor repro shown on that pic are NOT leds of the 80's.
Two things are what make them different from LEDs of that time:
1) High-Bright. These LEDs produce LOTS more light than any of the LEDs could in the 80's
2) They're white (or white/blueish IMHO). Those didn't exist then either.
The "real" FC used simple old-fashioned light bulbs....remember, Doc got the idea for the FC in 1955 !!!!