Sweet!
I actually have the same box in trailer form. Mine still had the vin tag on it. Mine is a 1955 Bell and Pacific telephone service box that was put on the ford f100 pickups.
My trailer is mostly done. Cut fenders, custom chassis with jk width 3500lb axle, 37" mtrs, jk rubi wheels, bed lined tub, RTT on top with bike rack, etc.
You will love it, or at least I love mine!
Post pix as it goes!
And side note if anyone knows where to find another one I am looking!!! I want to build another expo rig with it on the truck.