Acquiring means coming In to possession.
When you manufactured the firearm you case into possession of a firearm thru other means.
That's a twist of definitions.
If you bought an 80% receiver, you came into possession of a non-firearm part through an unrestricted, legal transaction. ( == "acquisition")
Then you manufactured the firearm from the part you legally purchased ( == "Not acquisition")
"by other means" doesn't have meaning on its own. You have to look at the entire sentence, which includes the phrase "shall acquire the ownership of a firearm".
So, the permit should not be required for a non-firearm acquisition. Once you mill it, and it becomes a firearm, it needs to be registered. If they want to require a PTA for that, too, it's a broad interpretation of the wording of the law.
Courts are inclined to interpret laws as narrowly as the law is written based on common usage and definition of the language, not in a broad catch-all manner.
"Acquisition" and "manufacturing, milling or creating" are not the same.
For your/HPD's argument to hold water, all firearms brought into the state by visitors or new residents would require a PTA, as would C&R firearms, which we know is not the case. Therefore, "any other means" is not a universal catch-all requiring a permit for every single firearm of which you come into possession.