Three months later, I finally had a minute to work on removing the carburetors, and a friend lent me a heat gun. The trick is the heat, prying, and patience. It's a lot warmer outside now too, so that probably helped. I considered it a great success when they popped off without anything being broken.
With the carbs removed, I now have room to clean and polish several hard-to-reach areas.
Below are three photos of the process. I was especially intrigued with a smear of yellow paint on one of the rubber boots. This same paint also appears on two bolts on the carb. Perhaps this was an error at the factory - an unsteady hand? To the best of my knowledge, this is the first time the carbs have ever been removed.
I am confident the carburetors will clean up nicely.