As you've posted from the Bostic case, here is the important part:
The quote from page 12 is from a dissenting judge, as such is meaningless in this case.A plain reading of the statute requires that, in order to be exempt, a firearm must be either manufactured in or before 1918 or be a "replica" thereof.
A replica is defined by Florida case law as meaning a reasonably exact reproduction of the object involved that, when viewed, causes the person to see substantially the same object as the original.
Applying this definition to the facts at hand, it is clear that merely having an ignition system similar to that found on an antique firearm is not sufficient to render a firearm a "replica" of a firearm manufactured in or before 1918.
The rifle possessed by the defendant, which included visible differences from an antique firearm such as a fiber optic sight, was not a "replica" of a firearm manufactured in or before 1918.
The appeals court upheld the lower court's determination of "Antiqueness" was correct. It never went to a jury, as it was a matter of law, not fact.