Body tub assembly

The body tub in my '75 is in urgent need of rebuilding, most of the floor is hacked up, the riser, the rear fenders, etc. The original seams and joints look like they were destroyed by whoever did a restoration job on it sometime before I bought the thing. Is there any documentation I can get hold of that shows how these things were originally put together? As simple as the rest of the rig is I suspect it's not that difficult, but I have no starting point for reference.