I think you're chasing the right rabbit in considering the fuel level in th bowl but I can't see it changing by being parked for a week unless it had a borderline problem already.
Thoughts/questions;
what specs did you use for float setting initially?
unoriginal carb or engine mountings require unoriginal float/fuel levels.
did you check for a float taking on fuel?that could change the fuel level after a time.
is the carb oriented such that the fuel level on deceleration forces would make the float/fuel valve open and temporarily flood the bowl/venturi?
does it act better if the idle mixture is as lean as possible?
how did you balance the carb air flow at idle to make them equal?

Bob Taylor