The cover for the airbox on this Honda generator hinges open to the left, but the frame rail is directly in front. The airbox is also bolted to the engine from inside (behind the filter).
I've throughly looked over this and there is no way to open that airbox unless you unbolt the engine from the frame, or perhaps modify the lid hinges with a saw so it doesn't have to swing as far to come off.
My first thought was ‘I would grind off the hinges before I would fuck with moving the engine’.
Depending on how hot it gets right there they may be able to use the self clinging velcro tape. (The kind with the hooks on one side and the loops on the other that people use for wrapping cables)