A rifle made before 1898 is no longer restricted by federal law.
For some reason the ATF and federal law see that a 108 year old rifle is no longer deadly and can by-pass the FFL. I'm not complaining at all.
If you look at a Sportsmans guide catalog, they sell a Turkish Mauser. They flat out tell you that anyone can own it and there are only a few restrictions.
Looking at the catalog, there is a No.38 restriction which states: Cannot be shipped to CA:HI:IL:NY Guam:Northern Mariana Islands or America Samona.
This is just Sportsmans guide policy. I being a resident of Illinois can recieve C&R rifles all day long as long as UPS\FEDEX is shipping.
So don't take their word for it.
If i were a bettin man, I'd say shipping an 108 year old rifle to Hawaii is legal. As i'm sure your brother the bird man has already lookd into the matter. Just makes sure you have read HI state law.
BTW, tell your brother to keep up with the Samson updates.