Japan was/is not a member of Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives (CIP)
A gun intended for the U.S. market would not require CIP proof markings ie. the fleur-de-lys.
I tried to find some images of other Kasuga action flats without success.
I think (an opinion which is worth nothing) that "Steel" means steel shot compatible IF the chokes are steel shot compatible.
Thanks Drew, your information is much appreciated. Because Japan was not a member of CIP, we would not expect to see a fleur-de-lys but hopefully we may see some other method of marking Steel Proofed. On the other Kasuga doubles that I've seen images of, there are no "STEEL" proofs. Each of the other Kasuga shotguns had a much lower serial number indicating my shotgun was a very late production. Perhaps the latest Kasuga's were proofed for steel and marked as such.
