Ken,
Certainly nothing wrong with a butt weld along the door jamb seam, however to avoid more mud on the exterior of the car. This is how I did it on my last Post Sedan, it`s a bit more work but a great result, having a bit more body work inside of the door vs. the exterior of the car. The welds to the (coupe) quarter panels are made while the quarter panel is still off of the car.
I also posted these pics because Phil (Woj) had asked to see pics.
Dan