Mark I think cushioning, cushioning, and more cushioning. is the answer. Heavy duty thick cardboard for the first box and as much cushioning material as possible between it and the second box. The HT-9 and the first box has to have some flexibility inside of the outer box. The outer box must be well strapped so it won't come apart.
I had the the HT-9's predecessor, the HT-1, shipped to me about a yearor so ago and the shipper really did a good job if he was shipping a big motor or engine. He had a beautiful wood pallet made and had the thing bolted down to the pallet with a cardboard box over the whole thing fastened to the pallet with wood screws. This method may have been ok for a big transformer or generator but not a radio. There was no give or cushioning so there was a lot of damage. I had it insured for what I paid for it so I was compensated, however it was a nightmare to get that accomplished. I have some ideas on that , but thats another story. Gud luck. 73 Wayne, N0TE