Maybe I am missing the point – Robert, I understand you just want a dust cover over the whole machine? Must it be a rigid material? Actually not sure what you are asking for, but if just a cover, then what about this: – I purchased the smallest one intended for a quad-bike – a motorcycle cover might also be suitable?
Its is a tough, waterproof material, stand up well to oils, etc ( well, after a year all still good) – has an elastic around the edge and pulls up close around the machine – comes in all sizes, from a large SUV to a moped.

