Yes. Of course you are spot-on with your info, Bert. And thank you for taking the time to post it.
And my apologies to Mark. I read his advice too quickly, and thought he was referring to the owners manual. SMH.
I hadn't even looked at the mower again until today. But, I found the source of the problem and it may help out other TB30 owners.
Upon the deck removal, The harness pigtail for the safety switch for the deck mulch plug/chute was pulled tight. Not terribly tight, but tight enough.
It turns out that this switch pigtail is teed off to the brake safety switch only about 2-inches away.
Well, the pressure on the chute pigtail was sufficient enough to "twist" the brake safety switch out of position just enough to where it was not depressing. (Yes, the brake safety switch can actually pivot if pulled on).
Thank you again, Mark and Bert. And I hope my experience can help others in the future........