There were two '54 Clipper models, the G and the S. The S was a rigid frame bike with no casquette, but the headlight mount was different, too. The G was a swing arm model with a casquette without pilot lights.
Those headlight mounts look like the one on the American "Indians" and would have dated the bike as a '55. Or it's possible the Aussies got something not quite the same as the homebrew stuff. Exports are not always the same as what the locals get! The "Indian" versions could have been what Enfield was using as their standard export model.
Bare