[Heathkit] Heathkit VF-1 Oscillator

[Jim Isbell]

I have just acquired a somewhat modified VF-1 on E-Bay.  It has had, 
what looks like, a geared knob added to the front on an offset panel. 
 When I get it I will know better exactly what has been done to it, but 
the internals seemed to be untouched in the photos.

Are there any modifications that I need to do to this VFO to make it 
into a stable usable VFO?