My Father and my uncle had a series of SW tanks where i grew up in sydney Australia, that they had been keeping since the mid sixties, then when i got old enough to start diving we set up another tank, i think it would have been around '84 or '85 and it was about 40gal. We caught fish at the beach down the road from where i lived. Not just some crappy little fish though, I'm talking lunar wrasse, different kinds of Chaetodons, lion fish and tangs. These were all sub gravel filter fish only systems with dead coral skeletons but there was plenty of natural sea water for water changes just down the street so everything survived pretty well.
I got my first full mini reef system with the spining spray bar, sump and bio balls in '96 and have pretty much just evolved from there.