Hi Larry, welcome to the forum
I'll initiate with a disclaimer: I'm a dreamer--an idea kind of person, with little to no experience in doing half the things I dream up. The following is what I might try if I were in your shoes. Not that I would know what I was doing.
I don't know how safe it would be to try this, and it would take something hefty, but I think you could build a counterweight into a case for it. Maybe a steel case...If you build up the base of the cabinet to fit cinder blocks (yes, I'm a redneck at heart) in it, however many it took to offset the imbalance, and secured that thing like Alcatraz... Or you could crush yourself (not just metaphorically) under the weight of an impossible attempt at beating the Big Business mark-up for the term "portable". Did I just rant?
Anyway, I would go check out some portable models and see how they're built. Lift the door, does it weigh much less than your model? See if it's in the weight of the door, or if the case is hefty enough to anchor it. Whatever you do, BE SAFE. Seriously, these things are so heavy they're meant to be on the floor, not suspended. Put the cash out for a portable model if safety is a threat.
Good Luck, and update us...preferably not from a hospital.