The /47 ( or any other numbers there) was Amals code for the contents of the carb , slid, mains, needle etc.
For a large part unless the carb is new in the box they are meaningless ( except to concourse zelot judges) , so forget about it.
You can fit any 389 part into any 389 body so just get the missing bits and fit them if you need them.
The lever on the frame is for the choke as you suspected.