Unusual cast warded keys with star section pipe

[Huw Eastwood]

Would be great if anyone can throw any light on these unusual cast keys. I've seen them crop up on eBay in the past, but sellers never seemed to know what they are from.

My guess would be padlock, but wondered if anyone knows for sure.

i can't imagine the front case of whatever it fits having the star section cut in it, as the section of the stem which turns would then only be guided by the end points. My guess would be the keys fitted into some sort of guide with the star shape cast in, a bit a like curtain or bolt thrower? Very crude keys but they've got me curious..