Hey cowtown- don't think you need to fill so much w/glass- a little more work on what you've done so far will yeild a smoother surface. If you have an area that doesn't fit too well, like behind the window where there is a couple unfilled areas, don't be afraid to cut that out in a more even peice- say, a rectangle, rather than trying to fit a bunch of little peices in... it will smooth out. Also, go slow as to not warp and cause more work and fill later. What you have is GREAT!!. Does the door fit okay? Then you're in business! Where is the v-butt you think needs leveled? Over the window or along the back? A few well-placed pie-cuts will help- (I think!!) Keep on Kustomizing!!
I haven't even messed with the doors yet....I was going to add hidden hinges and then worry about cutting it up. I was even considering making some tabs out of sheet metal and actually tacking the door in place so that I can cut and align everything...then add the hinges later. Tell me what you think. The V but is where the bottom of the rear window rectangle and the body meet. It is very noticeable where the curve on the side is.
Yes- tack the doors in place to get spacing and measurements- by the looks of your internal bracing you've thought this out and it WILL work! I see the back edge v you're concerned about- pie cut every so often (like you did the top on the outside rolled edge)- hammer/dolly to lay it flat, and weld slowly back in. You should be able to get it smoother. Don't be satisfied w/fiberfiller as it is an area that needs good structural integrity. Good luck and keep us 'posted'!