Wheel won't turn - Kit Car Porsche Speedster w/ VW parts

[tbrays]

Hi, am am trying to gain more knowledge of this kit car porsche speedster project of mine and I can't figure out why the wheel won't turn. It looks like there was a leak in the boot (is that what it is called?) the rubber thing on the axle behind the wheel. Is that what is preventing the wheel from turning? Also, there are two plugs that plugged into the back of the rotor and I can't figure out what purpose they serve. Any help is greatly appreciated. Thank you!