I have a d15b7 in a 95 dx and decided to have the valves done. Took the head off and took to machinist. Got it back and while prepping for new gasket, I ran my shopvac over one of the oil drain holes and heard a rattle. I looked down inside, and saw this: It has been there for a while. You could see on the lip inside the hole that it had been rubbed shiny about 2 mm deep. If this screw was any smaller..... Does anyone recognize this part and know where it came from?