I see two ways to go about this:
Option 1. Narrow the entire roof. The complication this causes is that the side panels will need to be modified to angle in at the top the same amount the doors angle in. This requires taking a pie cut out of the rear corners so you don't have to angle the barn door opening as well, and a bend along the entire side panel. This would be at the top of the door body, which is where the window hoops on the doors start angling in.
Option 2. Just narrow the front of the roof. If this were my project, this is what I would do. The roof is fairly easily narrowed at the front by taking pie cuts out of each side. You drew part of this option in one of your pencil sketches. Here's what it would entail:
I'd pie-cut the roof back to the rear of the doors. In the front, the widest part of the pie slice would be roughly 1.5", but you'd get the actual measurement by comparing the width of the roof (less drip rail) with the width of the top of the windshield; you want the roof very slightly wider than the windshield. So in the front it looks like this (before and after):
Viewed from the top back, the pie cut would look like this next set of images. You'd want to do the pie cut as close to the edge of the side curve as possible so you don't get a bend in the cross-recesses in the roof as you join the cut parts back together. You'd probably have to cut the curved side in order to get it to bend, and likely a small cut on the inside of the drip rail (more on the drip rail later).
So that gets the roof matching up to the windshield, now we've got to get the door surrounds to work right, because the CJ doors require that the sides angle in towards the top about 1.5", and the Postal sides are completely vertical. The correct shape for the door surround is for it to bend at the top of the door body and from there angle in towards the top 1.5". When mated to the straight vertical Postal side panels, this will result in a "step" between the door and the outside shell of the side panel, increasing towards the top, but I think that will look fine - it's not an uncommon design element of truck tops. Might look something like this:
This next photo shows what you want the door surrounds to look like, it's a Safari Cab door surround clamped to a Safari Cab side panel, they're both just out of the molds so they haven't been trimmed yet. Notice how the side panel angles inwards starting about 7" from the bottom; your Postal sides don't angle in so at the top there will be a "step" of about 1.5" between the surround and the side panel. I think it'll look fine, and because you need the surround to angle in to fit the door, if you don't like the step the alternative is angling in your Postal sides the same as this fiberglass side panel is angled.
This illustration shows what the "step" would look like; the red dashed line shows the outline of the drip rail of the roof after it's pie-cut.
About the drip rail - the Postal drip rail is excessively wide because it needed to cover the sliding door, which was outside the sides of Jeep. Since you've said the drip rail is rusty anyway, why not remove it completely and replace it with new sheet metal, maybe sticking out 1/2" or so? The super-wide Postal drip rail will detract from the final look of your top, so it's worth narrowing anyway.
Anyway, all of that is what I'd do. I think it's the method that promises the best chance for success, and the best look when it's finished.
What you can do is to convert your scrambler to a 1975 and earlier windshield frame setup. That one doesn't "curve in" at the top. It's just an idea but if u do it should mate up to this top much easier. It will also change the look though considerably and your wiper motor will have a bulge to the outside
