My experience goes back to early 60s. As mentioned corner box filters were the norm. All glass tanks were just coming on the scene, "invented" by a local from the next community. I met a man who had built his own 100 gal all glass tank. When I was 15, in 67 I built one my self, which still holds water. In fact I have a couple of 10s from the 60s in the basement. I still have a couple of heaters from the 60s that still work, and some airline. There were power filters available back then but were relatively expensive. When Hush air pumps came out from Metaframe, they were a huge hit because they were so quiet. They are the basis of the Hagen Elite series of filters, as the diaphragms are the same and the internals are too.
My first "tank" was a glass Exide battery case that was probably a gallon or a little more, that housed a large group of guppies. There was no filtration but lots of Vals that had to be thinned regularly. It was given to me by a women who had maintained it that way for several years. Next was a 10 gallon metal framed leaker, that I fixed and used for many years. In 67 I built the 28 gallon cube I still have and kept some cichlids that were given to me. In 1973, while at university. I bought a 32 gal for $15, and neons were 15 for a dollar. As well, UGFs were very popular in the late 60s, and they worked quite well, as they still do. So, while equipment has advanced in many ways, some things have remained the same. The Sodium Thiosuphite we used back then is the same ingredient in most dechlors sold today. I make my own now. I don't believe the chlorine level in the water has changed much if at all in the intervening years and there are still lots of people doing 50% water changes without using a dechlor.