[Amps] identification of surplus tank

[KD7QAE]

All,

I picked up this lovely tank assembly and an extra coil identical to the 
one in the tank as well last week at the Puyallap ham swap meet near 
Seattle.  The coil is wound on a large ceramic form approx 3" x 12" and 
is tapped in 5 places.  The coil wire is #8 AWG bare and silver plated.  
The inductance of the coil is approx 47uH.  The taps go to terminals on 
one end plate which are part of a large 6 position rotary switch.  The 
end plates are of some sort of hard insulator which is grey and has 
shiny flecks in it.  Mounted under the coil and parallel to it between 
the end plates is a 420pF air variable with approx 3/16 spacing.  This 
looks ready to drop into an amplifier as a tank circuit and mus have 
come from some sort of military gear from what I can tell of the 
markings.  One hint is that the coil is marked L5.  Any thoughts as to 
where this came from?

TOmm, KD7QAE