Disclaimer: I don't ship monitors (well, maybe one or two).
Claim: I do ship a lot of very delicate musical instruments, like tubas.
What I've learned:
Double-walled cardboard is a must. If you're shipping by truck and the
size of the item warrants it, it's even better is to build a crate (from
wood) and strap it to a pallet.
Bracing--the object must not be able to shift within its box. If an object
can shift, it will develop sufficient momentum to cause damage. Styrofoam
"peanuts" do not prevent shifting. It's far better to purchase some sheet
styrofoam insulation from a home improvement store and cut it to fit around
the object, within the box. Peanuts can be used to fill voids, but your
customer will love you if you first put them in a bag, so they don't
migrate all over the place.
If you have a particularly fragile surface, such as the bell of a tuba or
the faceplate of a monitor, invest in a cheap toy beach ball. Partially
inflate it and use it as a shock absorber--it will distribute forces far
better than anything else.
If anything can get loose (access panels, cords, etc), tape them down.
If it's a large package and you have access to passenger rail service,
consider Amtrak Express. Their rates and service can sometimes beat most
of the other common carriers--and your package will ride in a baggage car,
not be tossed off some conveyor belt used to load a plane.
---
Super glue may not be the best answer to reattaching those bosses. Try a
few drops of MEK or methyene chloride--the action on most styrene or
acrylic plastics will be that of a solvent. The cured join will be nearly
as strong as the surrounding material. Do NOT do this with transparent
plastics--it will fog them.
For whatever it's worth.
Cheers,
Chuck