GPW
Yes what you are seeing is 2x2x3/16 angel iron with the angle going in to the floor. Top of the floor
The two boards running front to back next to the fender wells on both sides sandwiches the angle iron to the floor.There are 1/4" bolts every 16" also there is 2x2x3/16 angle in the front and back side to side. Bottom of the floor
The floor is in three pieces two side one in the center. The tabs you are seeing are the axle and tongue mounts the wires are for the brakes. I hope this helps if you have any more ? just ask
Tim