Wes,
Perhaps somebody else can shed some light on this, but I personally am unaware of any private hatcheries that are verifying the genetics of their largemouth bass. To do this requires access to very expensive equipment as well as the knowledge of how to use them. State hatcheries in Texas verify their broodfish (and fish collected from state waters) using electrophoresis. A liver sample is required for this genetic test.
To claim that offspring are F1 hybrids, the hatchery must know that one parent is the northern strain, and one is Florida. They would also have to keep each pair seperate so that cross-contamination couldn't occur. It is very likely that this is not the case. A more appropriate term would be FX hybrids, indicating that they really don't know how much Florida genetics are present in the offspring.
Perhaps a minor point, but the "honest" portion of your question brings this practice into question. An honest fish dealer who does not verify genetics would say something like: "My bass contain Florida genetics, but I can't tell you how much".
