As for the 200s, the new one says SMC Pentax and the old one says Takumar. Also, the old one has a fluted, metal focusing ring and the new one has a focusing ring made of textured rubber.
The 165 is pretty much equivalent to an 80-85 mm lens on a 35mm camera. The thing is it has a leaf shutter, so you can use flash with much higher shutter speeds. The standard flash sync speed of a 6x7 without a leaf shutter lens is 1/30, so useless for fill flash.