I have a ladder at my campervan for use inside to get to the bed. I have used it before outside at the side of the van with towels around the upper part not to damage anything.
For that I made this thing. It consists of two parts. A clip that is put into the hooks at the top of the ladder and a plate that is put onto the clip. The plates are identical for both sides. The clips must be printed normal and mirrored. At least that was my shortsighted intention. But of course you can use both parts symmetrically, too.
I will put some foam on the plates not to damage the ouutside of the campervan.
This ladder was (is?) used with Carado campervans and probably several other types.
The clip needs supports. The plate does not. I printed it with 100% because the design is quite hollowed. But I think it wouldn't be necessary for strength.
I had severe problems with warping with the plate. Do everything your printer needs.