Wow. Well since you are missing the aluminum parts, you can't easily rebuild the door. At this point, you might have to get an entire new door assembly, not just the door (so door, screen door, and frame). There are a number of RV manufacturers in California that you could probably get a door assembly from relatively cheap (no shipping charges).
Another option would be to have one made. RV Parts, RV Parts Manufacturer ,RV Accessories, RV Windows and Custom RV Parts @ All-Rite
is in California somewhere and can custom make doors and parts for you, so they might be able to make you just the door. It may be almost as much as the whole assembly, but it would just be the door itself. Shipping on big parts like that is horrible, so if you could pick it up, it should be pretty affordable.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR