Not sure about the 3/4 sized guitars but my Yamaha FG150 is a small body, I guess concert or parlor size though the shape is not like most parlors. It took me quite a few years to find a hardshell case that would fit it. I still have the original case. It's a thin plywood case with very scant lining. If you can't find a case to fit, let me know the dimensions. This one may work for you, with some added padding??? If so, you can have it for the cost of shipping it.