metal shavings in a new motor are pretty common, and sometimes they get stuck in the pinch spot. you just force it to move again by moving to flywheel with your finger. its also posible that its hydro locked, in wich case you remove the glow plug and turn the engine over to clear the fuel from it. i wouldn't give up on the motor just yet.

you can flush the shavings out of the motor with some fuel. also you can rmove the backplate to inspect the motor for a broken con rod.