Hey OM:

Maybe you should looky at an old NTSC tv tuner. The brothers at RCA,
made sum tuners for the cable tv bands that went from 5Mhz all the way
up to 900Mhz

And they did it with quad matched varicaps, dual gate FET's, and a
PLL.

Not only did they control the VCO, but the TRF front end also.

Me thinks your OSC is way to efficient and your Q is way to high. Roll
the Q down with the right LC ratio or swamp it with sum resistance.

If you series varicaps you would increase the the amount of RF voltage
they could handle before starting to rectifry the RF.

73 OM
de n8zu