Carradice Classic saddlebag rack.

https://www.carradice.co.uk/products...saddlebag-rack

To mount something as big as a Camper you would saw off the bottom shelf. This piece is an absolute copy of the Karrimor Uplift. Karrimor made them with and without the shelf. In no case use the nylon web strap. Use proper leather capestrap.

My Karrimor is totally reliable and unimaginably simple for 54 years.