Box repairs and Gas tank

Been awhile since my last post. I have the gas tank mounted and need to finish off the lines,It is a Jeep Comanche tank and the filler will be at the left fender with a 47 Ford car filler door. I managed to locate a new fuel sending unit and fuel pickup it is all one piece.
The box was rusty so cut out pieces and welded in 16 ga metal,now will fasten the sub rails. Am using structural adhesive and the original rivits so it should be strong. Problem right now is finding a blue print of the crossmember and subrail locations,anyone know about that?
Now back to the garage.