If that's the roof overhang at the windshield,I believe fellow bolter Alan's57 had similar problems.
I realise there is the age difference but rot is rot,whether it's a '57 or a '64!
If I remember correctly, he had to cut out the rust and replace it with donor panels cut from a junk truck.
Here's a link to his
Photobucket page have a look through the pics or alternatively shoot him a PM.
I'm pretty sure he'll give you some good advice.
Good luck.
