More detail on my carb drying out problem

[Joe <jw@mitre.org>]

Looking closely at the carb, (a single Stromberg), it looks like where
the choke actuator is attached, there are several other holes around it.
Might this have been an automatic choke that was removed an a manual one
fitted? Could these holes be allowing fuel to evaporate? 

There is a large brass plug on the bottom of the carb - is this
something to open and drain periodically? (Not wanting to unscrew it
without knowing the sproing potential).

Joe