I hate to rain on your parade but it can cost a whole lot to ship a rifle from Australia ( And I assume NZ too) to the USA

I worked down under for some time and belonged to the local smallbore club. When I left they gave me my Club owned Gun , Anschutz M54 prone rifle.  My company paid all the expenses to ship my household home including the rifle. Our business is shipping and ran ships back and forth,  you would think I could have just put on one one of the weekly sailings.

No, You needed an export license from the Austrailan Army.  The exchange had to be OKed by the local police who certified I had an Austrailan shooters license and was the legal owner.  Normaly and the best method is to enlist the services of an export agent to handle the paperwork which I did.

Then it had to be shipped to a Licensed USA importer who had to enter it with Customs and certify it met all American regulations. I knew Neal Johnson the Anschutz importer who had already cetified that model and did the importation for me at no charge. There was some loophole that he worked on the rifle while in his possetion, all he did was look at the barrel and re-bed the stock. And he had to stamp the reciver with his companys name as importer of record. Then he had to ship it to my local dealer were I went through the normal records checks.

Our ship could not carry it as we did not normaly carry firearms and were not an approved carrier so we paid Air freight

The whole thing cost over 500 bucks, the same for one single shot .22 as if it had been a thousand rifles. Antiques are a little simpler but not much. Ony step you skip is the Army certification

There were some real bargins at local gun shops and shows.  Australia must have bought more Low walls than any other country. Many for sale in rough condition for under 100 US dollars. But it just did not pay to try to bring one home.

I recomend giving it up and buying a Ruger here.

Boats

Yes but that Ruger is not an antique.  Export from NZ may not be a problem but it can only be imported by a  Fed Licened importer.

You may be able to find one that will do it for you. I was lucky that the Anschutz importer used to be in our area and i knew him. Plus he does a lot of this for target shooters.