Original NPT plug used on 4-bolt mail blocks
 

Today, I went looking for my original plug ( the large one ) that
goes in the center hole above the oil filter on SHP engines.
Yeah, you guessed it - IT'S LOST!

Does anyone have an extra original one just looking for a
home? Shy of that, can someone post an image of one of these
plugs so I know what to look for?

Thanks,
Steve