Yes, that is an original finish. I have a 1959 kit (well, 22x14 bass drum and 12x8 tom with a mid-60's 16" floor) that were the same finish. Someone had done a terrible job with some rubbery vinyl wrap and sanded off most of the original lacquer for the failed refinish, but you could clearly tell the finish was originally exactly like on your snare.
I would strongly recommend keeping it the way it is. You'll notice a big letter M stamped inside the shell (probably next to a date stamp, if there is one). The M stands for either Maple or Mahogany, which meant that the shell was designated to be either lacquered or stained (or Duco finish) when it was built. These shells were made a little bit bigger in diameter than shells designated for a wrap, which have a P stamped inside, which stands for Pearl (Slingerland's collective name for all wraps). "M shells" designated for lacquering (like yours) received an extra thin maple ply on the outside to which lacquer would adhere better than mahogany. Shells designated for a mahogany stain received an extra mahogany ply.
My point is that adding on a wrap could make the shell too wide, resulting in it being very hard or even impossible to fit heads on the drum. I learned that one the hard way! The only way to wrap an M shell would be to first remove the outer maple or mahogany ply, which would only be possible through hours and hours of sanding, and the kind of patience not many people have. Even then, the shell is still wider than a P shell, but it can be done.
d.