[Premium-Rx] Harris/WJ help

[L D Ritta]

Hello Everyone

I have a board it has two crystal filters which looks like LSB and USB  and 
has room for two more.
There are 5 LM324N chips and the following number 14304 assy 
10121-5500 -5509E

Is this for Harris or WJ and what model is it for ? How do I remove the 
filters ,it has two nuts holding it on.
the filters are model number 21130 and 21131 cf-455kHz BW 2.7kHz
Could it be for the Harris RF-590A
Any ideas?

73 Lee VK5ABC