The grate nub has lasted nearly 3 full heating seasons of abuse since installing the piece of 5/8 steel in the shaker handle to balance the twisting motion of shake down. Tonight it finally gave up. Yep.. it broke again.. but now that I'm armed with a clever solution, I hope to never have this problem again.
Tonight at shake down it broke right as I was finishing. I didn't add any fresh coal. What's left will burn thru tonight and she should be cold by 1:00pm tomorrow when I get home from work so I can perform the surgery. My plan is to turn the whole grate set around and use another piece of 5/8 inch square stock to shove into the female end of the grate which will now be accessible at the front of the furnace. The 5/8 square steel will also fit into the shaker handle.. The female end of the grate is much more substantial than the male end that broke off, so this should be a winner and won't even cost me a new grate..
I'll revisit this thread tomorrow to post pictures of how this issue hopefully won't be a problem anymore..