Just re reading all your postings about the box......
 

....almost finished with my tailgate......and now Grant noticed that the hooks are mounted to a 1/4 inch reinforcement plate onboth sides of the tailgate...... the only rusted sample of a 42 tailgate (allegedly 42) did not have such a plate but it makes a lot of sense so will retro fit plates on mine. We revitted my tailgate but had to heat up each rivets cherry red to be able to hammer them in with the air gun...... not an easy job........

Overall my cargo floor was not as badly rusted as yours.....BUT...... we now find out, after building the tailgate and side as perfectly square as possible that my old cargo box had been abused with a resulting curve from front to back and side to side .....must have been owned by some Australian who overloaded it with 5 tons of wet green hay bales........ never realized how many details that need to be considered........ but Grant has as a 10 pounds sledge hammer that wins most arguments. We had 3 boxes to work from..... the best one was used as the basis of the resto and the other as guide /patterns.....BUT they are not all the same..... construction of the reinforcements that slip into the double return edges are different..... I have notice similar differences in cab 13....the reinforcements on some had a flat turned area that facilitated spot welding for assembly.......

They say getting there is half the fun..... but now I know it is twice the work!!!!!!

Thank God for all the pictures on MLU.