This carb is a 4777 650 mechanical secondary - lovingly referred to as the "double pumper". This carb is in pretty good shape over all - judging from the outside appearance. However - once opened up - you can see what leaving gasoline in a carb for long periods can do.
http://www.bangshift.com/forum/index.php?topic=15369.0
http://www.bangshift.com/forum/index.php?topic=15369.0