Yes, especially since I contacted the original manufacture of those crystals and they have told me they will only make 50 piece runs... Since I don't see the community restoring 50 Hickok pattern gens, I don't think Bliley will be getting any of my money but you never know- maybe they will find some stock on the shelf. I'm not holding my breath.
They don't even make anything under 1mhz anymore, so that makes the 315khz one unobtanium.
Manual:
http://bama.edebris.com/download/hickok/660/660.pdf