Made it back home to CDMX. It is illegal to bring used parts and you are supposed to declare them and potentially pay a fine and/or some kind of import duty. Every time I go to PHX I bring stuff back -- this time a set of carbs and two spare bodies, a petcock, some of the mounting hardware for the airbox and motor mounts. I waited for my bag to come through but... it never did. This means it's either lost or they are flagging it for inspection. They flagged it for inspection, but as usually happens the guy asked me to open up my bag and show him. I explained that I have a bike here, can't get parts, showed him pictures that included the Mexico City license plate, and he said, like all the others have said before him, every time it happens, "It's fine, just don't do it again."
I'll begin carb work tomorrow and hope to have the 550F up and running either tomorrow or Wednesday, rejetted.