Okay, since the grass has had a week to grow higher due to the rain we got earlier this week (darn old grass), I've got to go back to work on this connecting rod problem this weekend. So I've done my regular thing, and made a further attempt to answer my own question - and with a little help from the guys over at eHow
, I think I've got the answer.
The relevant answer seems to be found in their article How to Get a Flywheel Off a Lawn Mower Engine
. Although I haven't gone out to the garage to give it a try, it looks like I just need to use a gear puller-type tool, and laterally pull the flywheel off the driveshaft, by counterrotating the center puller tool bolt down against the top of the driveshaft. And the flywheel should just gradually lift off. Finger crossed.
Unless someone thinks differently, this will be be my likely strategy. I'll try to remember (at some point) to come back and post a confirmatory follow-up trumpeting my success.