I have the same problem on two Italian frames right now from the early 80's. A Pinarello Treviso and a Bianchi X4. In both cases, the fixed cups will not move for the life of me. Any recommended for loosening these? They are both 7400 series dura ace with 36 mm flats on them. I've blasted them with liquid wrench for the time being.
Houston, TX (Clear Lake)
Pinarello Montello SLX & Woodrup Giro plus two naked frames with stuck fixed cups!