Hi
I have some similar problems. I have a 1930 SR. When I got it the hood frame was rotten and needed parts replaced. As you say the visor part is a bit strange. The top does not clamp tightly to the top of the windshield - there is a gap and I have a sort of flap that is about 1.5 inches. The flap covers th gap, but, of course, let's water blow in when moving.
What I have done is found some metal clips so I can clip the flap to the top of the windshield and this works ok, but I am sure it is not correct, so I am interested in any other solutions.