Tom said his inductor was 100 -200 uh so I used 100 uh and 200 uh and made two plots.
If a fellow had Elsie (LC) installed on his machine it might be an interesting exercise to run the numbers on the circuit feeding the Xtal filter. It just may be a bypass filter on the Xtal filter input?
Hey that was our plan a high pass on the input shunting it to ground and a low pass feeding the Xtal!!! They stole our idea 65 years ago!!!
Seriously if you look at the circuit as having a PI filter feeding the Xtal and a PI filter exiting the filter I think you will be on the right track.