Your rear has been swapped to an Eaton with electric shift. More than likely it also has a higher GVW rating then the Corporate vacuum 2-speed that came in your truck. How fast is your truck, it may have good road gears and could run 65 mph or more...
Most vacuum tanks I've seen are about 8-10" diameter and about 24" long and are mounted under the step on the passenger side.
If you no longer have anything that is vacuum driven than all of that abandoned piping can be removed.
The 2-speed valve is mounted to an ell bracket with two bolts, remove and replace the bolts and you're done.
The original Hydrovac (brake booster) was mounted separate from the MC. Yes you have a dual pot MC as seen by the two lines coming out of the side of the MC. I don't know the vintage, but it's newer than the truck...
Mike B
