[Amps] series-connecting a split-stator variable cap

[Scott Townley]

I have a dual (split-stator) 20-100pF air cap, 0.040" gap (so ~1500V)
I need a single 15-50pF, 3000V for a tank tuning cap.
So is there any reason I can't simply series-connect the split stators and 
float the rotor?  Obviously the rotor must be isolated from the chassis 
now, and I won't get 20/2=10pF min due to frame effects, but I only need 
15...anything I'm missing?
TIA,