Here's how I would do it if I really felt a need, which I don't.
Macrame a handle out of paracord. Truss the amp around and around, like your Grandma would tie a brown paper wrapped package with string, with the tails of the macrame handle and onwards around the cabinet.
You really don't want to be transporting it with the speakon poking out the back of the cab but you can stuff that end under the string and leave the other plugged in the back of the Elf to satisfy the combo fetish.