Ok guys, thanks for the help so far.
Here's the pictures:
First, the thermostat and water pump.
Does this show you what you need to see?
Next: the side of the block.
Sorry that ?#1 is obscured by the throttle linkage. There's nothing attached to it and it stands out from the engine on a boss about 1/2 to 3/4 of an inch tall. I'm thinking it has to do with the water jacket, or maybe pedal linkage?
?#2 is a thread-in plug (closeup below)
?#3 is an undrilled boss.
And finally, the closeup of 2 and 3:
Hope this helps clarify things!
Cheers,
Tom