The proper way to deal with the screech of Mafac centerpulls is to treat them like a "feature" not like a "bug".*
When properly tuned, Mafac screeches can discourage the most aggressive dogs.
The Mafac screech is also a much under-rated weight-saver as it eliminates the need for a bell or horn.
Amir (* see the fine print in your Microsoft license agreement for more details) Avitzur Ramat-Gan, Israel