I had a piece of .015" thick german silver (nickel silver - there's actually no silver in it - it's nickel and copper and some other elements in small percentages). Here's what I came up with lacking a template. It does work, but the doubled over section that hits the pin is too thick to spring up once the pin is lifted (ie, once the standard is retracted fully into the body). So, right now, you need to hold the door down while cranking the standard back the last half inch or so.
The shutter curtains on this camera are nearly perfect actually. They were filthy but after I washed them down gently with a little warm water they're clean and fully light tight, and the shutter works well throughout the range (although who knows how acurately). I'm not sure I'd bother with it if the shutter wasn't functional.
I'm referring to the little sunshade curtains on the front that keep the door from springing all the way up. They also seem to have some sort of a plastic coating on them - more like a shellac than rubber though. I see there's a bar screwed into the standard that holds them down on the bottom and on the top they're pressed/glued? under the sheetmetal lip on the door. I'm not sure I want to try prying that lip up and then reforming it so I may try just a bead of silicone adhesive. I'm not sure what material to use - maybe I'll contact Fred Lustig and see if he has something.