Looking for a Zenith varactor tuning module

[drh4683]

Im looking for a zenith varactor tuner p/n 175-1503 for a 1973 zenith console with the 25DC56 chassis (horizontal, flat solid state). This is the 2nd generation varactor tuner zenith used. I have an apparent AGC fault with the tuner, and after troubleshooting the set, I had proper voltages at the chassis, so I suspected the tuner as the troublemaker. I have an indentical set in a different cabinet and pulled the tuner out as a sub to prove if the tuner was truly at fault. The set works fine with the other tuner, so Im hoping to find a replacement to bring this set back to life. I can't service the 1503 as the board and components are coated in epoxy. Any help is greatly appriciated. Thanks!