We have a '76 Exciter 440 that still runs like a charm and goes about 65...thinking about putting it in the vintage race that they hold at Lambeau Field or just selling it!
Those older Exciters are great sleds. I have a '79 in mint that I put up for sale on here last year, but didn't generate any interest. I'll just keep it for my son and admire the older classic. Very fast sled for it's time.
I'd keep it. You will never get much out of it to justify selling it. I'm in the process of restoring mine. The '76 was white correct? Post up some pics i'd like to see it.