You can fit the inner bevel cover from an 850/1100/1150 final drive to give you the black plastic spray cover. If the huger fits to these it would get you away. If you want pictures I've got one in the garage.
I have the small standard fitting spray catcher on my 1150 GSA, but I also have the full Pyramid Hugger.
The Pyramid fits to the disk caliper mounts (longer hex mounts with drilled & threaded ends are used). That would be more difficult to fit to an Airhead.
Are you wanting to protect those following - or your gearbox ?? .