Just remember the cabinets also support the roof! Hopefully you won’t have snowfall before you finish? Or maybe the trailer is under cover…
Also, since you’re taking them out, this is a perfect time to
fiberglass or epoxy wooden cleats to the interior of the shell, to which you can screw the cabinets when you reinstall them.
In this way you can avoid using the rivets through the shell and those holes can be sealed over. Much nicer☺️