WTB variable Aircapacitors for HF Amplifier

Hi Need Aircap for HF Amplifier,
Perhaps from ded HF Amp.
Loading and Tuning cap.
Please specify air gap and capacity, and dimensions.
Ideal would be 250 pf 3 or 4 Kv and 500 to 1000 pf @ 500 Volt or so.
If you have good band switch let me know too.

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