I'm an absolute nut on body gaps so have developed a procedure that works well. First is remove EVERYTHING from the door, hood, trunk lid, whatever, and see if it will center in the hole. If it does then adjustment needs done which may require slotting, twisting, heating/bending, etc. If it (the door) doesn't fit then material needs added to fill the gap or ground off the edges for clearance. If ground one will have to run a bead to join the three layers of metal back together. Example of a 37 Chevy coupe with a 39 Buick deck lid.
1937 Chevy Business Coupe braced well before panels replaced:
[img]https://i.postimg.cc/94tGV9qk/Jay-s-37-019.jpg[/img]All gaps are EXACTLY one paint stir stick wide:
[img]https://i.postimg.cc/PpHnpgJx/Jay-s-37-chevy-007.jpg[/img]Body molding lines and gaps must be EXACT:
[img]https://i.postimg.cc/8stgcnSp/Jay-s-37-chevy-002.jpg[/img]
