First, congratulations on getting all the screws out of the pot metal trim ring, most have at least one that breaks or the pot metal threaded boss it fit into crumbles. I did mine before it was painted so I had better options over one with the final finish on it. We used two heat guns, one on the trim ring and the other on the inner cab panel and also used longer screws so we could work our way around and around pushing on them in turn as the heat built up. It was really stuck but finally started to let loose in several areas so one could work each direction from those areas. That trim ring is fragile after 74 years and also rare and pricey if broken. After it's off you will see that it is the screw bosses (towers) that hold the ring in position, not the screws.
