Hi All,  Thanks for the tips on removing the Ampico secondary valve
rings.  Heat does the trick.  I ended up using an old electric iron,
turned upside down and set on "linen" temperature.  I then placed the
valves, ring down on the iron and let them sit for one to two minutes.

At that point, the shellac on the top of the valve block is softened
and can be cleanly removed with a knife blade.  Then the ring can also
be popped out by alternately applying inward pressure all around the
ring with the knife blade and prying up against the slight lip on the
outer rim of the ring.  After going around once or twice the ring is
easily worked free.

Again thanks,
Pat DeWitt