May be a silly question, but I assume you used the "rod" tool to align all 3 lever plates on the mechanism? If they are slightly mis aligned, won't allow the reverse gate.

I'm 55 now, no time to waste. Not a week goes by that I don't hear about someone passing on.Let's get out there,smoke some tires,have a beer with a good friend,do what you have always wanted to do.I am pretty sure no one will ever say on their deathbed "gee I'm glad my life was calm and boring"