Yep. It's on the same side of the engine as the shift lever and at the opposite end of the engine. The Westerbeke manual (
here) around page 98 or so says it's a pipe plug, so no gasket, I'm guessing.
Should be obvious to your weapons of choice.
Good call, Joe/Marty.
You don't by chance see a pipe plug in the bilge? Or maybe the PO removed it in a crude attempt to change the oil?
Don't pull anything just yet, I'd say...
Bill