Al,
There are no castings for Dumas ballast that I am aware of. The keel is far too small for todays standard ballast to fit. Hickman is no longer in business.
I do not know one who has reworked and EC12 ballast to fit. I am sure it can be done. Today and since the 95 Standard the keel ballast are all very similar so it would not matter which one picked to rework it.
Also, I show no listing in the Class Registry with a Dumas hull #662. What is the sail number?
...94