A year ago, my neighbor gave me his table saw when he moved. Not having a table saw I was happy to get it but there seems to be a part(s) missing or damaged for the fence. It was all in parts when I got it and I believe I have everything he gave me but the fence will not lock in place. What mechanism that is there baffles me as there is a knob on the front side that when pulled, lifts the pin up which seems backwards to me. Does anybody recognize this fence and know what parts are missing? I don't do much wood working but need to make a few things for the flatbed and my shop. Thanks for any help!