I've been in touch with Chris from slammedpanel.com for quite a while regarding a ladder that can stay on the bus while driving. I measured my rack and bus and sent him a technical drawing, he built the ladder for me. My rack is different to the ones he is assembling, so not an easy task regarding the exact position on the stiffer body panels!
Received the ladder a few days ago and the fixing strap today. Sits and looks perfect, at least in my eyes! Great guy and craftsman, get in touch with him if you're keen on such a ladder or a HWE style rack! Many thanks again Chris!