As Stewart stated in today's work thread, I re-installed the hydraulic drive motor today. It still weeps oil around the shaft, because I wasn't able to get a new seal. I have ordered a new motor and will be here Wednesday. I do not plan on installing it until after work weekend unless the tamper is unused for a half hour or so Saturday morning.
The hydraulic brake idea hit me this morning on the ride down. I don't know why we didn't think of it before. Simple. But not very effective when the hydraulic unit is not running.
So Dave, here is your task training. I took photos for visual aid.
Brake off. Handle is forward.

Brake on, handle pulls toward the operator.

Of note, if the brake is on, the drive motor will not move. I would suggest not using the brake unless needed, and not to rely on it while the machine is not in use.
Also this brake should not be used to stop the machine like a regular brake would be. Doing so could do damage to the drive components.
I am designing some Fairmont style wood block brakes for a better fix than my current brake set up.
Also, the top rack was re-installed. I am planning a revamp on this also. Ut still brushes against the other side harder than I wouls like to see. A little tweeking will take care of this at some point.