That being said, I would chop the power of the offending engine and go airborne
What does the auto brake system do? Don't know you type, just asking and thought for consideration. For the 737, it is not described clearly what will happen if ONE thrust lever is retarded.
I would probably go airborne without touching anything and solve it in the air. Most likely it would be a faulty indication:
"Only multiple failures could allow the engine to go into reverse thrust."
If not:
"The EECs prevent power above idle if the related thrust reverser has moved from the stowed position."
I am just saying that if being to creative, you might be in for some suprises.