Jeff,

 

Using the FAA database:

 

 

And searching "Model" with the following text, the number of planes registered (not necessarily all flying) is noted:

 

LANCAIR.....................................1009

LANCAIR IV.........................292

LANCAIR IVP...............223

LANCAIR IVPT...............16

LANCAIR ES.........................58

LEGACY.............................118

LANCAIR LEGACY.........85

LANCAIR 360.......................123

LANCAIR 320.......................212

LANCAIR 235.........................99

LANCAIR 200...........................6

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totals...................................908    1009

 

Who knows what model is used for the missing Lancairs.  The IVP and IVPT are sub-counts of IVs.  All but 1 of the LEGACYs are LANCAIRS, but the model "LANCAIR LEGACY" is only seen in the sub-count.