There's no rings on that motor. But if you found metal fragments that's not a good sign. Did you take the whole motor apart? You should be able to see where they came from. If everything looks ok, and the bearings look ok then it should start. Low compression will make it hard to start, but it should run. Just have to set the idle up higher.

Take the high speed needle off and flush that out, low speed needle as well. New fuel line, or at least cut 1/8 inch off each ends of the fuel supply line. Set high speed needle 2 1/2 turns from closed, and low speed needle 1 1/2 from closed. New glow plug, and good igniter should get it running.

But any metal found in an engine is a bad sign of stuff to come.

*edit* The exhaust doesn't push the fuel up. It just helps stabalize it in the tank. Compression in the motor sucks it up. It'll run fine without the pressure line even attached.