I realized i have one of the airborne repackaged BC-221 which i should put on Ebay soon. I had the newer gen version of the het freq meter, the one with builtin AC supply, but i gave it away. I have maybe the last such type freq meter, the one transistorized with film strip freq readout. USM-169, i think ? 

BTW, I have a junker or 2 of LM if anyone needs a cabinet.

I also have the Japanese HF and VHF similar devices, but like much of WW2 Japanese electronics, these are just sad in comparison. I have the Japanese "HRO equivalent" and i am still deciding whether to keep the HF one with it, to enhance the overall collectibility. ( BTW, some past issue of CQ had a pix of this receiver - WRONG. That is not it. AFAIK only photo is at Yokohama Military Radio museum. )

Oh - but i digress. I think any trimmer cap in your freq meter could easily adjust fot the very small gate pF of the FET. We are talking small signal devices here.

-Hue Miller