I am at work, so carb is not in my hand. However, I am very confident that the portion of the carb you described in detail above is installed correctly. You have exactly identified the carb and it does have an extra fuel filter as well. The diffuser is removable and is in place just as you described.
The only 'choke' parts I have left are a spring, a white plastic piece with a hole in it the size of the tension cable, and a brass piece that also has a whole in it the size of the tension cable. I also have a brass washer that I thought was to be used to secure the end of the choke tension cable to the TOP of the carburetor. I know this must be wrong. I'll be home in an hour and will get a better description of the pieces.