You are absolutely right! I got a chance to check it out again after work, and realized that the bleeder screw is part of a small port that attaches onto the engine via 2 10mm screws. I just unscrewed those off and 'lightly' banged the port off, no fuss.

Looking back (and the noob that I am at this), I had a completely different picture in my head when I wrote the first post and used the incorrect term: 'engine block'. Sorry for the confusion, and thanks for the help! Much appreciated; I really didn't want to have to buy a new engine and swap it... at least, not right now .