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Are these black celluloid, clear, or colored?

When applying heat to black celluloid, when it starts to turn brown....you have started to cause them to degrade.

They are not like plastic, which...

Celluloid is highly flammable....so, don't use fire to un-bend the scales. Perhaps boiling water.

Are you sure it's not just that the blade is off centered?

Personally, I'd replace the scales....