The 175 is an early 172 with the GO-300 geared engine. It was a higher revving engine than the ordinary O-300 so wore out faster.
The 177 is the Cardinal which had a cantilever wing with no struts. It was available with a variety of engines from 180hp upward. Some were fixed gear some were retractable.
The 195 is a lovely 1940's radial engined beauty.