I finally had some time to tinker a little more.

I wanted to get an all-up weight of the engine-muffler-carb-magneto combination before I started cutting metal and plastic.
To do this I had to get rid of the gas tank. To remove the gas tank either cut the plastic back plate or remove it and re-install.
I chose to remove and re-install.

During this process I also took off the heat shield for the carb and the muffler. The heat shield for the carb also doubles as a gasket. You can easily see the hole in the case and the gasket for the pressure pulse that allows the carb to pump.
Below are the weights with all components minus the gas tank and the weight without the two heat shields.

It started out right about 5 lbs. Removing the two heat shields dropped 2 oz.