Welcome to the site Pano!
That's a nice looking Power Wagon. I'm wondering if that box might
be of a later vintage [mid '65 to '68] ?

Does it look like the
rear tires are "crowding" the fronts of the wheel wells? Just curious.
I'm interested in knowing about those wheels.... Are they 17.5" or 16" ?
If they're 16" an not a split ring wheel, they'd be a pretty rare item. You
can look up your VIN number on the Sweptline.com site. Click on the history
section and it should provide the link for the VIN decoder.
If your wheelbase is 122" [noted on the VIN tag], you have a W200.
That looks like a transfer case driven Braden LU-2 winch on your truck.
They're pretty handy! Give us some particulars on the engine, etc. and
keep the pics coming.
John