Looking at accordions on ebay and for sale other places I've noticed there was a time when waterfall keys seemed popular. Oddly though on some really older accordions they are not waterfall styled and are more square, so they didn't start that way. Did waterfall keys go to the wasteside in the mid 40's? Is it safe to assume if you see them its pre 1950? Was there a reason to "switch" to them? and then back from them again? Does anyone really prefer or like them? I always stay away from them, and prefer beveled edges even.