[FStephenMasek]

The secondary of the third IF transformer was open! Fortunately, I had a NOS Philco 45-6365 Universal IF Transformer in stock, so installed it. It now works properly.

The finished chassis bottom, with the cover off
[Image: http://i269.photobucket.com/albums/jj77/...nished.jpg]

Detail of the new IF transformer. Since the new transformer has internal trimmers, I removed the original trimmer for the 3rd IF primary.
[Image: http://i269.photobucket.com/albums/jj77/...d%20IF.jpg]

The new transformer atop the chassis. This is probably exactly the repair which would have been made if somebody had taken this radio to a Philco repair shop a few decades ago.
[Image: http://i269.photobucket.com/albums/jj77/...d%20IF.jpg]

The old IF transformer. Both wires to the secondary looked good, and I did not see any external signs of distress, although a spider had lived there.
[Image: http://i269.photobucket.com/albums/jj77/...d%20IF.jpg]