For interested readers, there is a technical discussion taking place regarding these problems of late 1920s Cadillacs on the EarlyV8Cadillac Yahoo forum. Some members are contemplating remanufacturing in more stable metals. Feel free to join in order to participate and benefit:
http://groups.yahoo.com/neo/groups/EarlyV8Cadillac/info
Regards, Michael Barnes
EarlyV8Cadillac list owner