Junk item removed from a Nihon Dempa Kogyo crystal filter 5MHz selective level meter

This is a 5MHz crystal filter manufactured by Nihon Dempa Kogyo.
I obtained it over 20 years ago as a junk item from an Anritsu selective level meter and kept it in storage. Since I have no plans to use it, I would like to pass it on to someone who can utilize it.
I will include a copy of the circuit diagram for the relevant section of the selective level meter from the same company with a different frequency band, as well as the preceding and succeeding amplifier circuit boards. Although the circuit diagram shows 50kHz due to a different model number, the product is a 5MHz filter.
The bandwidth is very sharp, and when it fluctuates around ±1kHz, it seems to be around -10dB, but please consider this as a reference only, as it was checked by an amateur with uncalibrated equipment.
I plan to ship anonymously via Takkyubin Compact or Yu-Packet Plus.
As this is an old item and is being sold as junk, please purchase with the understanding that returns will not be accepted even if there are issues with the product upon arrival.