That brace in your first picture to the back of the hinge pocket is going to be in the way. Also it appears to be an attempt to hold the floor in position. I don't think that's really necessary, as you can locate the floor at each A pillar and make sure it's flat all the way across. You should also install some diagonal bracing across the door openings and at the A pillars across the front. Otherwise it looks like a good start.
For locating the floor, you can use dimensions from the FAM from the upper hinge bolts (or some other known point) down to the floor. Mark the A pillars at the floor elevation to give you a reference for the new floor pieces.


Kevin
1951 Chevy 3100 work truck
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1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.