Digital Filter Needed for Assemblage DAC

Does anyone know where I might find a Burr Brown DF1704 digital filter for an Assemblage DAC 2.6?
These were originally made for SF/Assemblage as an upgrade for the PCM 100 digital filter which originally came with the DAC 2.6 or DAC 3.0, and can be used with either. When The Parts Connection closed down, these filters were sold off, and I am hoping someone may know of a dealer out there who bought some of them and would still have one. I have already checked with SF and with the new Parts Connexion, neither of which have one.
Thanks for any help you can give me.

Tim Mitchell