Lamp is from The late 1800s according to the top. There is no WIC, and I have not tested it.

Both knob and oil cap move freely. The knob that adjusts the WIC needs a bit of jiggling, but it does move up and down completely. It gets a little harder halfway through turning.

The lamp is nickel plated, and shows signs of age. The surface needs a deep polishing. See photos.