Although I have never tried it, I wonder about the possibility of brewing
your own ceramic filter from some of Murata's 455KHz ceramic resonators.
Although not the Q of a quartz crystal, it may be worthwhile. I have some

I've done this with ceramic filters in tube circuits. You definatly
need to match the impedence to the tubes wich is high both for plate
and grid. What I did for that was to use a transistor IF can, filter,
IF can wired so the high impedence side was to the grids and plates.
Worked very well in a tube RX like the mighty midget.

For transistors the matching for those filters is IF can to get the
high collector impedence down to 1k range then the filter into the
base of the transistor. FETs get treated like tubes.

Allison
KB1GMX