Have fun making it all fit together. Been there done that- here are some comments to help you avoid some pitfalls.
Find some original parts and stuff will just work. The repro stuff is not so good. You are going to have some fit issues! I went with not so good original pan to have some starting point in my car.
If you are doing a rumble seat do not forget to put the rumble stop bracing on the bottom side of the seat pan. They need to be welded down tight as it needs to keep a rumble lid in place.
You will need to bolt everything down very tight and test fit. A real pia to get functional.
Some minor details. The repro curved rear panel should have oval head screws. The repros are flat so you need round head screws. The front edge of the rumble panel was riveted to the top of the cross sill. The rear edge of the rumble floor pan is riveted to the front edge of the cross sill. If you have vol 6 of the How to Restore Your Model A you will find some details in the 68C article. All original lower rear outside panels would have a hole for the rear spare. It was plugged when side mounts were installed. You need to be careful on spacing the bottom edge of the rumble lid with repro panels. The original lid bottom curved up to the edges and the lower rear panel curved down.
At the shows most cars get all these part wrong and they do not function properly. No hole for spare means repro lower panel, they also have chipped paint at the corners where the rumble lid hits because the gap is too tight.
Some helpful picts are here:
Rumble lids