[Boatanchors] Need SSB filter for 50 year old botanchor

[John King via Boatanchors]

As the RE says I have a 50 year old Heath HX20 transmitter with a defective SSB filter.
I am searching for crystal filter from a Heath HX 20 mobile SSB transmitter or one from a Heath Marauder SSB transmitter. The original filter for these transmitters was manufactured by Blackhawk filters of Janesville, Wisconsin. The filter is a 4990 Kc filter.
If  you have a parts HX 20 or Marauder I would be interested in a parts unit with filter or just the filter if it is still in good shape.

Crystal filters suffer from age and it might be difficult to locate one that is still good. If you have a filter for the HX 20 or Marauder, please contact me directly . Thanks and 73, John, K5PGW