I thought this was a good way to ship axles to Austraulia.
Took months to get there. Arrived intact too!
https://m.youtube.com/watch?v=dA7nP94W51M
I have been trying to outsmart USPS when I ship sets of rebuilt, or core shocks, with some mind boggling damage avoided so far.
Bolting down the shocks to a plywood base works good.
The reinforced shipping tape helps.