Upon closer examination of the engine on a recently purchased '79 Hunter 27 with a Yanmar SB8, I found that there appears to be a plate missing on the bracket that holds the alternator! This bracket bolts to the starboard side of the engine. The missing plate covers a "hole" into the water chamber around the cylinder. There is also a threaded hole below the "hole", similar to the one for the temperature sensor above, but this hole doesn't have anything in it. Would the removal of the "plate" and a threaded object have been part of a "winterizing" procedure? Where can I find a new "plate" and whatever screwed into the threaded hole? Thanks in advance for your help!