He wanted to ship it in a palette crate. I could imagine a FedEx loader driving a fork lift into it. I helped someone else figure out how to use two boxes for shipping me a larger Rick Nielsen numbered RNK Korina to me no problem. He even made it thinner.
When I shipped a Standard to Switzerland 20 years ago, I went a local packing and shipping store that makes custom boxes using a fabrication machine with a ton of presets. The guy who knows it all there took one look at the Standard case, without taking out his tape measure, and said out loud "baby bed mattress box." He took me to a small stack in their warehouse - said they kept them in stock for people moving and/or storing baby beds in attics between childbirths.
Takeaway: Check in with your local mattress superstore, they may give you an adequate box before they dumpster or recycle it.