HRS134-3 (b) Every person who acquires a firearm pursuant to section 134-2 shall register the firearm in the manner prescribed by this section
since I did not get the firearm by 134-2 it does not require registration
Registration was not mandatory for rifles and shotguns acquired in the state of Hawaiʻi prior to July, 1994.
Incorrect, did you even read 134-2?
§134-2 Permits to acquire. (a)
No person shall acquire the ownership of a firearm, whether usable or unusable, serviceable or unserviceable, modern or antique, registered under prior law
or by a prior owner or unregistered, either by purchase,
gift, inheritance, bequest,
or in any other manner, whether procured in the State or imported by mail, express, freight, or otherwise,
until the person has first procured from the chief of police of the county of the person's place of business or, if there is no place of business, the person's residence or, if there is neither place of business nor residence, the person's place of sojourn, a
permit to acquire the ownership of a firearm as prescribed in this section.
So you got it as a gift "or in any other manner", you need to have a permit to acquire, which means you need to register it (per 134-3).
I wouldn't count on police to know the law. If you have questions on stuff like that, state AG is the place. If you have a letter from them that's a different story.