Dear mr_byte31,
The circuit you posted in my opinion works as a impedance matching and as band pass filter too, however, it does not have a very good rejection to other frecuencies. I think you could try with a low pass filter. An easy filter to do which has good rejection for upper frecuencies is the Pi filter, it has only 3 passive parts (two variable capacitors and one coil) with a Pi filter you could have around of 20 to 26dB of rejection for 2nd and 3rd harmonic frequency.
I hope you can solve your question.
Have a nice day.
Best regards,
Juan