Once again, thanks for the assistance guys.
Mait, my angle grinder holder was much to cheap and wimpy to even begin to hold the sprockets. Thanks for the idea though.
Resi, Looking forward to seeing the tool you made. It appears that it would be difficult to get any tool into the space for the upper balancer sprocket.
Rob, I know, power tools are your friend. I have an electric impact wrench that's old but remains reasonably functional. I keep telling myself that someday I'll buy an air compressor and a few pneumatic tools to make all that bolt twisting go a bit more quickly.
Anyways.....here's what I did:
I discovered that one can use the flywheel bolt on the crank and the installed balancer chain to hold the balancer shaft sprockets.
Fit a tubular spacer about 25 mm or so behind the flywheel attachment bolt on the crank shaft. This keeps the bolt from bottoming in the crank threads and makes it easier to remove at the end.
Tension the balancer chain....this is IMPORTANT since with no tension on the chain system, the chain will slip over the crank sprocket teeth and throw off your balancer timing.
Since the crank and the balancer shafts rotate in opposite directions you can now hold the 17mm crank bolt while applying a torque wrench to the balancer bolts.
NOTE: Be careful here and observe the chain slack. Slack still develops in the chain run between the crank and the upper balancer sprocket. Too much slack and the chain will slip......Incrase the tension in the system.
Then you can use an impact wrench (either powered or hand held) to remove the bolt in the crank shaft. You have to do this in order not to disturb the balancer shaft bolts. A few taps and the crank bolt comes out and you can now continue to assemble the rest of the left case bits.
......and , if you're like me, you will put everything together, stick a new gasket onto the left outside case and as your gathering the case bolts you'll notice that the long chain guide that goes on the upper part of the balancer chain is still on your bench....
...then you get to take everything back apart again to install the chain guide..
So, the bike is back together, oil added and running. I ran out of daylight to actually test ride it other than just up and down the street.
Sure sounds different at least. In place of a bit of rattling noise, there is a nice pleasant "whine" coming from the left case. At least it SOUNDS smoother.
More after it warms up a bit this morning.