You've run into the same brick wall many restorers/hotrodders have over the years. As far as I know there is not a replacement "patch" or complete piece that can be had. This is a much more complex piece than you can imagine and is sandwiched between the upper roof and side panels of the body. That's why you see so many cars with "short" gutters or "funny-looking" thick ones.
Perhaps HK has a solution that does require years of expertise in metal work and fabrication.
thanks guys for your opinons &info on drip rails . i have a 40 buick with shaved rails & the ford i wanted to leave stock. it' not a car i plan on keeping so may be i' let the next guy worry about it. thanks !