The 64 has a lot in common with the earlier model (engine color, drum brakes), so it makes sense that the carb spacer would be the same.
The PCV should make the engine run better. It keeps the crankcase under a vacuum which helps to keep the rings seated.
Getting rid of the stink is a huge positive. I've only recently gotten my car running after several years, and although I've owned many old cars in my younger years completely forgot (perhaps more correctly never considered) how much they pollute. Now that I have a house with a basement garage I have spent considerable effort to get mine as clean as possible.