If you take the handle off and drop the bailer to the open position I think it will drop back from the hinge and part of the frame.
You can take the bailer apart by removing the rivets and replacing the rubber gasket. Then re rivet together again.
Watch out with WD 40 on the rubber, it may perish it.
I use Vaseline on the side of my bailers, small smear is all thats needed!
CP